Bugfix/release cleanup (#512)

* Lots of cleanup on the warnings in the solution. Deprecated IsLastWriteLessThan and made a new method HasFileBeenModifiedSince.

* Added some tests for the new extension method.

* Changed filter import to use correct import

* Scan Series now uses Refresh Metadata for Series, rather than library one.

* Fixed an issue where cover generation wasn't properly taking forced update into consideration. Removed a case of cover generation for no reason.

* Fixed series downloads not triggering backend call

API/Controllers/ReaderController.cs

@@ -368,7 +368,7 @@ namespace API.Controllers
         /// <summary>
         /// Removes all bookmarks for all chapters linked to a Series
         /// </summary>
-        /// <param name="seriesId"></param>
+        /// <param name="dto"></param>
         /// <returns></returns>
         [HttpPost("remove-bookmarks")]
         public async Task<ActionResult> RemoveBookmarks(RemoveBookmarkForSeriesDto dto)