Add project plainui views

src/plainui/jinja2/plainui/components/list_projects.html.j2

src/plainui/jinja2/plainui/project.html.j2

src/plainui/jinja2/plainui/projects.html.j2

src/plainui/locale/de/LC_MESSAGES/django.po

src/plainui/locale/en/LC_MESSAGES/django.po

src/plainui/urls.py

src/plainui/views/__init__.py

src/plainui/views/projects.py

src/plainui/views/rooms.py