:sparkles: Broader image support for file serving

[aaronleopold]

Relates to #339

This PR adds support for more image formats embedded in supported media types. This does not relate to thumbnail generation. I've also refactored the corresponding DB queries to be more performant and readable

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 12.72727% with 96 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
apps/server/src/routers/api/v1/library.rs	0.00%	34 Missing :warning:
apps/server/src/routers/api/v1/series.rs	0.00%	27 Missing :warning:
apps/server/src/routers/api/v1/media.rs	0.00%	21 Missing :warning:
core/src/filesystem/content_type.rs	60.86%	9 Missing :warning:
apps/server/src/routers/opds/v1_2.rs	0.00%	5 Missing :warning:

Files with missing lines	Coverage Δ
core/src/filesystem/common.rs	52.56% <ø> (ø)
apps/server/src/routers/opds/v1_2.rs	0.00% <0.00%> (ø)
core/src/filesystem/content_type.rs	81.47% <60.86%> (-1.68%)	:arrow_down:
apps/server/src/routers/api/v1/media.rs	0.00% <0.00%> (ø)
apps/server/src/routers/api/v1/series.rs	0.00% <0.00%> (ø)
apps/server/src/routers/api/v1/library.rs	0.00% <0.00%> (ø)

[aaronleopold]

I'll aim to review and merge this over the weekend