Misc Polish (#1569)

* Introduced a lock for DB work during the scan to hopefully reduce the concurrency issues

* Don't allow multiple theme scans to occur

* Fixed bulk actions not having all actions due to nested actionable menu changes

* Refactored the Scan loop to be synchronous to avoid any issues. After first loop, no real performance issues.

* Updated the LibraryWatcher when under many internal buffer full issues, to suspend watching for a full hour, to allow whatever downloading to complete.

* Removed Semaphore as it's not needed anymore

* Updated the output for logger to explicitly say from Kavita (if you're pushing to Seq)

* Fixed a broken test

* Fixed ReleaseYear not populating due to a change from a contributor around how to populate ReleaseYear.

* Ensure when scan folder runs, that we don't double enqueue the same tasks.

* Fixed user settings not loading the correct tab

* Changed the Release Year -> Release

* Added more refresh hooks in reader to hopefully ensure faster refreshes

* Reset images between chapter loads to help flush image faster. Don't show broken image icon when an image is still loading.

* Fixed the prefetcher not properly loading the correct images and hence, allowing a bit of lag between chapter loads.

* Code smells

API/Controllers/LibraryController.cs

@@ -213,9 +213,11 @@ public class LibraryController : BaseApiController
     {
         var userId = await _unitOfWork.UserRepository.GetUserIdByApiKeyAsync(dto.ApiKey);
         var user = await _unitOfWork.UserRepository.GetUserByIdAsync(userId);
+
         // Validate user has Admin privileges
         var isAdmin = await _unitOfWork.UserRepository.IsUserAdminAsync(user);
         if (!isAdmin) return BadRequest("API key must belong to an admin");
+
         if (dto.FolderPath.Contains("..")) return BadRequest("Invalid Path");
 
         dto.FolderPath = Services.Tasks.Scanner.Parser.Parser.NormalizePath(dto.FolderPath);