Update `get_serializer_class` to consider the request method

[pamella]

Description: Describe in a couple of sentence what this PR adds

• Update get_serializer_class to consider the request method. See the updated docstring.
  • If the request method is GET, it tries to use self.read_serializer_class.
  • If the request method is not GET, it tries to use self.write_serializer_class.
  • If the specific serializer class for the request method is not set, it falls back to self.serializer_class.

[!NOTE]
Once this PR is approved and merged, I will open another one updating the package version so we can publish it to PyPI.

Dependencies: dependencies on other outstanding PRs, issues, etc.

Resolves #1 Resolves #17 Resolves #44

Merge deadline: List merge deadline (if any)

N/A

Installation instructions: List any non-trivial installation instructions.

Testing instructions:

• On a local testing project, get the changes made, and access the API in the browser:
  • Make sure the page renders properly.
  • Make sure GET and non-GET requests (such as POST) work properly.
  • Configure a swagger and make sure the UI works properly.
  • Test views using a mix of serializer_class, read_serializer_class, and write_serializer_class.

Screencast from 23-05-2024 16:55:32.webm

Reviewers:

• [ ] tag reviewer
• [ ] tag reviewer

Merge checklist:

• [ ] All reviewers approved
• [ ] CI build is green
• [ ] Version bumped
• [ ] Changelog record added
• [ ] Documentation updated (not only docstrings)
• [ ] Commits are squashed
• [ ] PR author is listed in AUTHORS

Post merge:

• [ ] Create a tag
• [ ] Check new version is pushed to PyPi after tag-triggered build is finished.
• [ ] Delete working branch (if not needed anymore)

Author concerns: List any concerns about this PR - inelegant solutions, hacks, quick-and-dirty implementations, concerns about migrations, etc.