[CLEANUP] Renaming Stuff #2436

[PoppyBlossom]

About The Pull Request

This PR contains some name changes suggested by #2436

• gender -> sex (to remove confusion around what this is)
• ID -> cat_id (should be lowercase and id is taken by a Python builtin)
• favourite -> favorite (Murica) [CLEANUP] Cat config files moved to, surprise, CatConfig #2437 (Done Already)
• mate -> current_mates (in line with current_apprentices and the poly update)
• previous_mates -> former_mates (in line with former_apprentices and former_mentor)

Part of: #2436

j-gynn mentioned that they don't need help with their project but renaming stuff is really time-consuming, so I guess I can help a bit?...

[j-gynn]

Hey, thanks a bunch (/gen) for helping! I think the senior devs may close this PR as we're currently in feature-freeze (only accepted PRs right now are bugfixes and art/writing content). However! Very grateful for the help.

Are you in the Discord server? Would love to have a chat and see if some of the parts of this can be formally "allocated" to you to save me doing them too by mistake 😂 You'd also get access to beta testers, which are almost essential for major internal changes like this one to make sure we don't miss anything (ask me how I know. I definitely didn't corrupt a bunch of people's saves with my first ever pushed PR to this repo, nope... /s).

Also, just doing some testing - since this modifies the JSON save terms it causes a fatal bug when you try and load a save made from this branch. For now, I'd suggest reverting the JSON changes - once all the desired changes to cats.py have been made, then we can go through and make a new version of the JSON and update the save converter to make all those changes.

[PoppyBlossom]

Thank you so much for the advice! I am not currently on the Discord server, but I will try to join as soon as possible.