♻️ Refactor media API into multiple modules

[JMicheli]

This is just a reorganization pull request, it does what a TODO comment suggested and removes everything in the (very large) single-file media.rs module out to a directory and separates the bulk, individual, and thumbnail operations.

It also removes all the apply_* filters from media and into a separate filters module (again, as suggested by the TODO). I also did the same for other such functions in other places to keep things organized.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1681 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
apps/server/src/routers/api/v1/media/individual.rs	0.00%	669 Missing ⚠️
apps/server/src/routers/api/v1/media/bulk.rs	0.00%	282 Missing ⚠️
apps/server/src/routers/api/v1/media/thumbnails.rs	0.00%	211 Missing ⚠️
apps/server/src/routers/api/filters/media.rs	0.00%	206 Missing ⚠️
apps/server/src/routers/api/filters/series.rs	0.00%	119 Missing ⚠️
apps/server/src/routers/api/filters/metadata.rs	0.00%	112 Missing ⚠️
apps/server/src/routers/api/v1/media/mod.rs	0.00%	43 Missing ⚠️
apps/server/src/routers/api/filters/library.rs	0.00%	39 Missing ⚠️

Files with missing lines	Coverage Δ
apps/server/src/routers/api/mod.rs	0.00% <ø> (ø)
apps/server/src/routers/api/v1/emailer.rs	0.00% <ø> (ø)
apps/server/src/routers/api/v1/library.rs	0.00% <ø> (ø)
apps/server/src/routers/api/v1/metadata.rs	0.00% <ø> (ø)
apps/server/src/routers/api/v1/mod.rs	0.00% <ø> (ø)
apps/server/src/routers/api/v1/series.rs	0.00% <ø> (ø)
apps/server/src/routers/opds/v1_2.rs	0.00% <ø> (ø)
apps/server/src/routers/opds/v2_0.rs	0.00% <ø> (ø)
apps/server/src/routers/utoipa.rs	0.00% <ø> (ø)
apps/server/src/routers/api/filters/library.rs	0.00% <0.00%> (ø)
... and 7 more

[aaronleopold]

Thanks for tackling this! It's hard to get to each TODO I write, so I really appreciate you knocking it out. I didn't look too closely at the existing and relocated code, I'm going to trust it was moved without edits which seems to be the case for the handful I did scan through. I had a couple of unimportant questions, but they aren't blocking.

Oh I also renamed the PR to have more contextual meaning

[JMicheli]

Okay I think that fix addresses the only issue here. I'll let CI finish then merge late tonight unless you indicate otherwise.