chore: enable flake8-django (DJ) rule in ruff config

[afuetterer]

Description

This PR is an attempt to enable the flake8-django (DJ) rule in the ruff config.

The first and easiest fix was to reorder method and manager declarations to have the order the ruleset expects them

What do you think about these rules?

• DJ001: django-nullable-model-string-field
• DJ007: DJ001django-all-with-model-form

To me both rules make sense, but we could also ignore them.

DJ007 would mean to explicitly name all fields that are exposed through the modelform, which might be a good idea anyway in case not all of them should be exposed?

DJ001 would mean to alter the model fields (add default="") to TextFields and generate new migrations. To me the rule makes sense: not to have an empty string and null possible for TextFields.

But what do you think?

rdmo/conditions/admin.py:13:9: DJ007 Do not use `__all__` with `ModelForm`, use `fields` instead
rdmo/questions/models/question.py:26:11: DJ001 Avoid using `null=True` on string-based fields such as URLField
rdmo/questions/models/question.py:36:16: DJ001 Avoid using `null=True` on string-based fields such as CharField
rdmo/questions/models/question.py:41:15: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:71:18: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:76:18: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:81:18: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:86:18: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:91:18: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:96:18: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:101:18: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:106:18: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:111:18: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:116:18: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:121:26: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:126:26: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:131:26: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:136:26: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/questions/models/question.py:141:26: DJ001 Avoid using `null=True` on string-based fields such as TextField
rdmo/tasks/admin.py:15:9: DJ007 Do not use `__all__` with `ModelForm`, use `fields` instead
rdmo/views/admin.py:15:9: DJ007 Do not use `__all__` with `ModelForm`, use `fields` instead
Found 21 errors.

Related issue: #766

Types of Changes

• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)

Checklist

• I have read the contributor guide.
• My code follows the code style of this project.
• All new and existing tests passed.

Tasks

• resolve DJ007 violations
• decide whether to resolve or ignore DJ001 violations -> resolve
• resolve DJ001: replace null=True, blank=True with blank=True, default=""
• generate new migrations
• fix failing tests: create new fixtures
• rebase branch
• re-create migrations

[afuetterer]

Created new questions fixtures, using:

python manage.py loaddata fixtures/*
python manage.py makemigrations
python manage.py migrate
python manage.py dumpdata questions | python -m json.tool --indent 2 > questions.json

[afuetterer]

Rebased and ready for review.

[afuetterer]

Can we merge this @MyPyDavid?

[MyPyDavid]

Yes please, I have approved already right