Merge branch 'lowercase-tags' into 'develop'

src/backoffice/forms/assemblies.py

src/backoffice/forms/events.py

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

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

src/backoffice/views/assemblies/assemblies.py

src/core/forms/projects.py

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

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

src/core/models/tags.py

src/core/utils.py

src/plainui/views/general.py