POLIO-2013 integrated campaign api

[quang-le]

What problem is this PR solving? Explain here in one sentence.

Related JIRA tickets : POLIO-1997, POLIO-2013

Self proofreading checklist

• Did I use eslint and ruff formatters?
• Is my code clear enough and well documented?
• Are my typescript files well typed?
• New translations have been added or updated if new strings have been introduced in the frontend
• My migrations file are included
• Are there enough tests?
• Documentation has been included (for new feature)

Doc

In the tests

Changes

• Add PrimaryKeyRelatedField to CampaignSerializer
• Add custom validation for both integrated_to and integrated_campaigns
• Add RetrieveCampaignSerializer to format front-end friendly response
• Add tests

How to test

• Using Django API, Bruno or Postman:
  • Get details for a campaign: the fields integrated_to and integrated_campaigns should be present
  • Update this campaigns:
    • Update integrated_to with another campaign's id and save
    • Update integrated_campaigns with a list of campaign ids and save

Expected behaviour:

• integrated_to must be a polio campaign id
• integrated_campaigns cannot contain polio campaigns ids
• integrated_to must be null for a polio campaign
• integrated_campaigns must be empty for non-polio campaign
• if a campaign has multiple campaign types, it is considered a polio campaign if polio type is included in its types

Print screen / video

NA

[tdethier]

I forgot to include a general comment in the review so here it is @quang-le:

• I couldn't make POST/PUT calls to the API with the DRF web view because I never was able to provide a valid value for Grouped campaigns - GET calls are fine and behave properly. Since it's not related to this PR, it's fine I guess
• I added many comments in units tests, but it's more or less the same thing:
  • I would add more asserts on value in the DB to make sure that the result is ok in the system and not just in the returned payload
  • I would check the error message in case of a validation issue (to make sure that you are actually triggering the right error and not another one)
• the api.campaigns.campaigns.py file is so huge, I hope we can manage to split it in multiple files in the future 😅 it will also make our lives easier in unit tests if we can cover the viewset behavior in a separate file from the serializers behavior