🐛 Fix various thumbnail generation issues

[aaronleopold]

There are a good amount of other changes in this diff, e.g. upgrading the rust version, some crates, clippy fixes, etc:

• Upgrade image-related crates
  • This required upgrading rust version to 1.79.0 (one minor behind the very recent stable). Multiple lint issues surfaced after the upgrade
• Add ProcessorError to (eventually) replace the FileError usage throughout the image processors. This was mostly because not all errors during image processing are file errors, and it would feel out of place to add them to FileError
• Added test images for all supported (and future supported) images for various tests
• Added tests to assert GenericImageProcessor behavior
• Added tests to assert WebpProcessor behavior
• Added tests where easily addable (e.g. user permissions, etc)
• Minimally improve client-side validation and reporting for invalid thumbnail configuration fields
  • The UI combined with the intersection types makes it a bit awkward, but is alright for now IMO
• Add a validate fn to the ImageProcessorOptions struct to enforce valid configurations server-side
• Remove remove_thumbnails_of_type and replace the single usage with remove_thumbnails to fix the issue where regenerating/removing thumbnails doesn't clean up thumbnails of differing formats than the configured format

[codecov]

Codecov Report

Attention: Patch coverage is 89.90826% with 77 lines in your changes missing coverage. Please review.

Files	Patch %	Lines
core/src/db/entity/user/permissions.rs	87.56%	24 Missing ⚠️
core/src/db/entity/user/preferences.rs	0.00%	9 Missing ⚠️
core/src/filesystem/media/pdf.rs	0.00%	9 Missing ⚠️
apps/server/src/errors.rs	0.00%	8 Missing ⚠️
core/src/filesystem/scanner/series_scan_job.rs	0.00%	8 Missing ⚠️
core/src/filesystem/image/thumbnail/mod.rs	0.00%	5 Missing ⚠️
core/src/db/entity/smart_list/item.rs	0.00%	4 Missing ⚠️
core/src/db/entity/notifier.rs	0.00%	3 Missing ⚠️
core/src/db/filter/smart_filter.rs	0.00%	3 Missing ⚠️
apps/server/src/routers/api/v1/library.rs	0.00%	1 Missing ⚠️
... and 3 more

Files	Coverage Δ
core/src/db/entity/library.rs	2.54% <ø> (ø)
core/src/filesystem/content_type.rs	37.85% <ø> (ø)
core/src/filesystem/image/generic.rs	100.00% <100.00%> (ø)
core/src/filesystem/image/mod.rs	100.00% <100.00%> (ø)
core/src/filesystem/image/thumbnail/manager.rs	0.00% <ø> (ø)
core/src/filesystem/image/webp.rs	100.00% <100.00%> (ø)
core/src/opds/v1_2/entry.rs	43.60% <100.00%> (ø)
apps/server/src/routers/api/v1/library.rs	0.00% <0.00%> (ø)
core/src/db/entity/metadata/page_dimension.rs	85.91% <75.00%> (ø)
core/src/filesystem/image/error.rs	0.00% <0.00%> (ø)
... and 10 more

[aaronleopold]

I'm aiming to have time tomorrow to re-validate the fixes in this PR, then I'll merge it in. I'll start prepping the next versioned release within a week or so after that point.

[aaronleopold]

I just tested the following without issue:

• Updating library thumbnail config, initialize regeneration (keeping old thumbs)
• Delete all thumbnails (old and new thumbs affected, different formats)
• PNG, JPEG, WebP generation without issue, individually

Added a small fix to correctly render the library settings form according to fresh update

[JMicheli]

This looks awesome - no issues on my end when testing.

I have a minor suggestion in my review comments both otherwise LGTM.