OPDS Flattening (#1904)

* Flattening OPDS Structure

# Changed
- Flattened OPDS structure to reduce user taps.

* Fixing format

* Fixing book series titles

* Optimized file size to use pre-calculated data to avoid an I/O touch.

* Fixes #1898 by aligning all content headers to the correct MIME types

* Remove dead code

* Fixed a bug with continue point where it fails on chapters or volumes tagged with a range

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Co-authored-by: Robbie Davis <robbie@therobbiedavis.com>

API/Services/ReaderService.cs

@@ -495,7 +495,7 @@ public class ReaderService : IReaderService
         // NOTE: If volume 1 has chapter 1 and volume 2 is just chapter 0 due to being a full volume file, then this fails
         // If there are any volumes that have progress, return those. If not, move on.
         var currentlyReadingChapter = volumeChapters
-            .OrderBy(c => double.Parse(c.Range), _chapterSortComparer)
+            .OrderBy(c => double.Parse(c.Number), _chapterSortComparer) // BUG: This is throwing an exception when Range is 1-11
             .FirstOrDefault(chapter => chapter.PagesRead < chapter.Pages && chapter.PagesRead > 0);
         if (currentlyReadingChapter != null) return currentlyReadingChapter;