feat: Ability to have "Automatic Removal" be set up for only certain directories

[mkulina]

Example: Having certain folders/directories where you have channel content not be auto removed, or be able to adjust auto removal per directory.

I may have my default as stuff I watch on the daily.
Other content might be for archiving reasons, etc.

[dialmaster]

I like this idea, it would go with the other Channel Settings and should be fairly straightforward to implement.
@mkulina Since you suggested this, you are welcome to pick it up as one of your next issues, if not I'll pick it up when I have time.