Enforces uniqueness of (verified) email addresses across all users. Email
addresses are compared case-insensitivly and Unicode-normalized. The new
unique constraints are disabled by default and can be enabled with a CLI
command. They are planned to become mandatory in uffd v3.

A lot of software does not allow multiple users to share the same email
address. This change prevents problems with such software.

To enable this feature run the command:

  uffd-admin unique-email-addresses enable

The commands reports any issues (e.g. existing duplicate addresses) that
prevent enabling the feature.

This change also introduces a generic mechanism to store feature flags in the
database and improves error handling for login name constraint violations.

0bd26ee8 added __init__.py files to the tests subdirectory. This had two
unwanted side-effects:

1. setuptools.find_packages() recognised the tests as a package, so they were
   included in the pip and Debian packages.
2. The Debian package build process with dh_python automatically runs tests
   with unittest. Unittest's test discovery (in contrast to pytest) only works
   if __init__.py files exist, so this step did not do anything in the past.
   Now, failing tests caused the whole CI pipeline to fail very early without
   the helpful information provided by later stages.

This change disables running any tests during the Debian package build. It also
explicitly sets the package list to "uffd".

Restructure tests into views/models/commands subdirectories to mirror the new
source tree structure introduced with ac731bf4 (Restructure source tree).

Deprecates old case-sensitive format. Some software out there stores email
addresses converted to lower case, breaking v1 remailer addresses. The new
format is case-insensitive and generally more robust.

Uffd continues to use and support the v1 format for services setup before
this change. Support for the old format is planned to be remove in uffd v3.
It is possbile to gradually migrate services to the new format with a service
setting in the admin interface.

Also fixes compatability issue with very recent SQLAlchemy versions introduced
by b391e176 (whens parameter of case function).

Also fixes a minor email-related bug in the admin interface and bad
texts/translations in the selfservice UI.

Access control is done via normal api credentials.
See README.md for details.
Adds an optional dependency on python3-prometheus-client.

Preperation for future features that require per-service user settings
or state, e.g. stateful sync or service-specific email settings.

The additional JOIN of ServiceUser degrades getusers API performance
by 30-50%. For API calls that return many users, this is compensated by
an otherwise unrelated optimization (selectinload instead of joinedload).

Convert DateTime fields to UTC, use "utcnow" instead of "now" and use
babel helper/filter when dates/times are displayed or parsed from user
input.

Uffd continues to use the system's timezone in the user interface by
default.  However, it is now possible to overwrite this with the
BABEL_DEFAULT_TIMEZONE config option.

Unittest jobs now fail if any test fails. Unittests on Bullseye no longer
fail due to jinja2 import errors. Linter jobs run faster.

Move all models, views, cli commands and templates into corresponding
top-level folders. Detailed changes:

- uffd/<NAME>/models.py -> uffd/models/<NAME>.py
- uffd/<NAME>/cli.py -> uffd/commands/<NAME>.py
- uffd/<NAME>/views.py -> uffd/views/<NAME>.py
- uffd/<NAME>/templates/* -> uffd/templates/
- uffd/ratelimit.py -> uffd/models/ratelimit.py (it contains models)
- gendevcert from uffd/__init__.py -> uffd/commands/gendevcert.py
- profile from uffd/__init__.py -> uffd/commands/profile.py
- cleanup from uffd/tasks.py -> uffd/commands/cleanup.py
- roles-update-all from uffd/role/views.py -> uffd/commands/...
- Views from uffd/__init__.py -> uffd/views/__init__.py
- All models can/should be imported from uffd.models
- flask shell auto-imports all models instead of only a few

The old structure was meant to keep the code modular and related
code/resources close to each other. However, the modules turned out to
be heavily interdependent and not very modular. Also importing was fragile
due to ordering issues.

With the new structure the dependency tree is much simpler: Infrastructure
code (top-level *.py files) has no internal dependencies. Models only
depend on infrastructure and other models. Views and cli commands depend
on infrastructure, models and other views/commands.

Going forward there is still some restructuring to do, e.g.:

- Move mfa setup views to selfservice views
- Move mfa auth views to session views
- Move utility code from views to infrastructure (e.g. login_required)
- In most cases views should not need to import from other views
- Reorganize infrastructure code

With this feature, uffd can be configured to hide mail addresses of users
from certain services while still allowing the services to send mails to the
users.

To these services uffd returns special remailer addresses instead of the real
mail addresses. When a service sends an email to a remailer address the mail
server queries uffd's API and replaces the remailer address with the real mail
address in both envelope and headers.

This feature requires additional mail server configuration (Postfix
canonical_maps) and support in uffd-socketmapd.

When the "new invite" page was submitted with e.g. an invalid "Valid Until"
value, uffd displayed an error and reset the whole form. This was confusing
to users.

Now the form content is preserved on errors. Also the "Valid Until" field now
has min/max attributes to prevent submitting the form with invalid values.

Fixes #134

The group and role update subcommands set the description to an empty string
if the "--description" option was ommitted.

Fixes #156

Closes #152

Co-authored-by: davidc

Closes #150

When the service overview was introduced, it was meant to be optional. Thus
if the SERVICES config option was empty (the default), uffd returned 404.

Commit fa67bde0 (Migrate OAuth2 and API clients to database) introduced the
regression that accessing the service overview page when no services are
visible based on the permissions of the current user (or guest if not logged
in), 404 is returned.

This change fixes the regression and further changes the behavior to improve
consistency. Since fa67bde0, the page is relevant to admin users regardless of
the SERVICES config option. Therefore uffd asks for login or reports missing
permissions in all cases it originally returned 404.

Added guard to first v2 migration in order to prevent accidental upgrades.
Extended the upgrade instructions and moved them from the README to a
standalone file.

The original change completely broke single logout support.

The migration now uses the correct hashing algorithm (unsalted SHA512 instead
of salted SHA512) for OAuth2/API secrets/passwords.

The migration originally failed to convert the passwords/secrets to the
format expected by PasswordHash resulting in invalid password hashes. With
this change, the migration works correctly.

Also fixes minor template bug.