Add unique constraint to database plugin names

[Donnype]

Changes

Add unique constraint to database plugin names and align API behavior

Issue link

Closes #3547

Demo

QA notes

Please check you cannot create two plugins with the same name from Rocky!

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Code Checklist

• All the commits in this PR are properly PGP-signed and verified.
• This PR only contains functionality relevant to the issue.
• I have written unit tests for the changes or fixes I made.
• I have checked the documentation and made changes where necessary.
• I have performed a self-review of my code and refactored it to the best of my abilities.
• For any non-trivial functionality, I have added integration and/or end-to-end tests.
• I have included comments in the code to elaborate on what is not self-evident from the code itself, including references to issues and discussions online, or implicit behavior of an interface.

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Checklist for code reviewers:

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Checklist for QA:

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[ammar92]

Tiny remark and good point from @underdarknl. Looks good otherwise 👍

[stephanie0x00]

QA notes:
I'm very much not allowed to create two plugins with the same name, as the application throws a stack trace. It would be more user friendly to have an error message in the UI specifying that this is not allowed.

Environment:


Request Method: POST
Request URL: http://127.0.0.1:8000/en/aa/kat-alogus/plugins/boefjes/add-variant/nmap/

Django Version: 5.0.8
Python Version: 3.11.10
Installed Applications:
['whitenoise.runserver_nostatic',
 'django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.humanize',
 'django.forms',
 'django_components',
 'django_components.safer_staticfiles',
 'django_otp',
 'django_otp.plugins.otp_static',
 'django_otp.plugins.otp_totp',
 'two_factor',
 'account',
 'tools',
 'fmea',
 'rocky',
 'crisis_room',
 'onboarding',
 'katalogus',
 'django_password_validators',
 'django_password_validators.password_history',
 'rest_framework',
 'tagulous',
 'compressor',
 'reports',
 'knox',
 'csp']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'whitenoise.middleware.WhiteNoiseMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.locale.LocaleMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'rocky.middleware.auth_token.AuthTokenMiddleware',
 'django_structlog.middlewares.RequestMiddleware',
 'django_otp.middleware.OTPMiddleware',
 'rocky.middleware.auth_required.AuthRequiredMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware',
 'rocky.middleware.onboarding.OnboardingMiddleware',
 'csp.middleware.CSPMiddleware']



Traceback (most recent call last):
  File "/usr/local/lib/python3.11/site-packages/django/core/handlers/exception.py", line 55, in inner
    response = get_response(request)
               ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/core/handlers/base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/views/generic/base.py", line 104, in view
    return self.dispatch(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/contrib/auth/mixins.py", line 109, in dispatch
    return super().dispatch(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/views/generic/base.py", line 143, in dispatch
    return handler(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/django/views/generic/edit.py", line 151, in post
    return self.form_valid(form)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/app/rocky/katalogus/views/boefje_setup.py", line 53, in form_valid
    get_katalogus(self.organization.code).create_plugin(boefje)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/rocky/katalogus/client.py", line 217, in create_plugin
    response.raise_for_status()
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/httpx/_models.py", line 761, in raise_for_status
    raise HTTPStatusError(message, request=request, response=self)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Exception Type: HTTPStatusError at /en/aa/kat-alogus/plugins/boefjes/add-variant/nmap/
Exception Value: Client error '400 Bad Request' for url 'http://katalogus:8000/v1/organisations/aa/plugins'
For more information check: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/400

[Donnype]

@stephanie0x00 Thanks! And: handling of this error in Rocky will be handled in several places in #3566