* Write subtitles using SubtitleEdit
We've been using SubtitleEdit to parse since 2021
https://github.com/jellyfin/jellyfin/pull/4984
I think it's time we start using it to write too
* Clean up ConvertSubtitles
* Add JsonWriter back
* Add support for VobSub subtitle streams
* update logic to determine separate extraction for VobSub subtitles
* simplify VobSub extraction logic and fix ffmpeg command
* Match `ExtractAllExtractableSubtitlesMKS` with `ExtractAllExtractableSubtitlesInternal` Matroska's VobSub option
* Add a comments clarify why MKS was used, and remove the redundant VobSub extension branch
* remove redundant VobSub format check
* fix type errors
* Cleanup extracted files
* Pagination and fixes
* Add migration for attachments to MigrateLibraryDb
* Unify attachment handling
* Don't extract again if files were already extracted
* Fix MKS attachment extraction
* Always run full extraction on mks
* Don't try to extract mjpeg streams as attachments
* Fallback to check if attachments were extracted to cache folder
* Fixup
Extracting a subtitle stream is a disk I/O bottlenecked operation as
ffmpeg has to read through the whole file, but usually there is nothing
CPU intensive to do.
If a file has multiple subtitle streams, and we want to extract more
of them, extracting them one-by-one results in reading the whole file
again and again.
However ffmpeg can extract multiple streams at once.
We can optimize this by extracting the subtitle streams all at once
when only one of them gets queried, then we will have all of them
cached for later use.
It is useful for people switching subtitles during playback.
It is even more useful for people who extract all the subtitle streams
in advance, for example with the "Subtitle Extract" plugin.
In this case we reduce the extraction time significantly based on the
number of subtitle streams in the files, which can be 5-10 in many
cases.
Signed-off-by: Attila Szakacs <szakacs.attila96@gmail.com>
Did a simple search/replace on the whole repo (except the RSSDP project)
This reduces LOC and should improve performance (methods containing a throw statement don't get inlined)
```
if \((\w+) == null\)
\s+\{
\s+throw new ArgumentNullException\((.*)\);
\s+\}
```
```
ArgumentNullException.ThrowIfNull($1);
```
