[Feature] Exclusion list for Categories

[sud0xenn]

In reference to https://github.com/Raival-e/Prism-File-Explorer/issues/157#issuecomment-3208866424

For consistent feature catalog, it would be nice to be able to maintain separate exclusion for categories. I'm aware you're busy and will be focusing on bugs etc but I'm just opening this issue for tracking purposes if someone wants to submit a PR. I still haven't gotten the time to look at the codebase and set back up my android dev environment to do it myself. Been busy having fun with testing the project.