(RUF012) Fixed mutable class Defaults- Task 2

[ananyakaligal]

Part of #10196
NOTE: These are NOT automated changes, they are done by hand
This pull request addresses Part of RUF012 Rule - Task 2, with a focus on enhancing code quality and resolving linting issues related to mutable class attributes.

Technical Details:

• Updated Files: The ClassVar annotations were added to mutable class attributes in two files, ensuring they are treated as class-level attributes. This change resolves the RUF012 linting issues.
• Remaining File: The update could not be applied to plugins/worksearch/schemes/editions.py due to a shared base class with the files mentioned in Task 1, which would introduce an overriding issue. Therefore, the change was not feasible for this file.
• Type Safety: Added proper type hints for better clarity and type safety throughout the affected files.

Testing:
Ran ruff check --select RUF012 to confirm that no further warnings related to mutable class attributes remain.

Screenshot:
N/A
Stakeholders:
@RayBB

[RayBB]

As far as I'm concerned this looks good.
However, I'm going to need to get a second opinion from staff

[RayBB]

@ananyakaligal I looked at this with Drini and we realized we probably don't want all these values to be mutable.
Can you review and add non-mutable options to this (unless it needs to be mutable).

See https://docs.astral.sh/ruff/rules/mutable-class-default/

[ananyakaligal]

@RayBB sure, I will work on this.

[RayBB]

@ananyakaligal any update on this?

[ananyakaligal]

Hey @RayBB, My schedule has been pretty packed, and I'm working on the preview button right now. The CSS part of that is a bit much and very specific, so it's taking some time. I'll definitely work on this by the end of this week. My apologies!

[RayBB]

No problem. Marking as draft until it's ready 👍

[ananyakaligal]

working on it

[ananyakaligal]

@RayBB I used MappingProxyType to ensure immutability, as I encountered dictionaries throughout and wanted to maintain consistency. Now, I will investigate the files where the class variable overriding issue popped up.