Scan Loop Fortification (#1573)

* Cleanup some messaging in the scan loop to be more context bearing

* Added Response Caching to Series Detail for 1 min, due to the heavy nature of the call.

* Refactored code to make it so that processing of series runs sync correctly.

Added a log to inform the user of corrupted volume from buggy code in v0.5.6.

* Moved folder watching out of experimental

* Fixed an issue where empty folders could break the scan loop

* Another fix for when dates aren't valid, the scanner wouldn't get the proper min and would throw an exception (develop)

* Implemented the ability to edit release year from the UI for a series.

* Added a unit test for some new logic

* Code smells

* Rewrote the handler for suspending watching to be more resilient and ensure no two threads have a race condition.

* More error handling for when a ScanFolder is invoked but multiple series belong to that folder, log it to the user and default to a library scan.

* ScanSeries now will check for kavitaignores higher than it's own folder and respect library level.

* Fixed an issue where image series with a folder name containing the word "folder" could get ignored as it thought the image was a cover image.

When a series folder is moved or deleted, skip parent ignore finding.

* Removed some old files, added in scanFolder a check if the series found for a folder is in a book library and if so to always do a library scan (as books are often nested into one folder with  multiple series). Added some unit tests

* Refactored some scan loop logic into ComicInfo, wrote tests and updated some documentation to make the fields more clear.

* Added a test for GetLastWriteTime based on recent bug

* Cleaned up some redundant code

* Fixed a bad merge

* Code smells

* Removed a package that's no longer used.

* Ensure we check against ScanQueue on ScanFolder enqueuing

* Documentation and more bullet proofing to ensure Hangfire checks work more as expected

API.Tests/Services/DirectoryServiceTests.cs

@@ -995,4 +995,20 @@ public class DirectoryServiceTests
     }
 
     #endregion
+
+    #region GetLastWriteTime
+
+    [Fact]
+    public void GetLastWriteTime_ShouldReturnMaxTime_IfNoFiles()
+    {
+        const string dir = "C:/manga/";
+        var filesystem = new MockFileSystem();
+        filesystem.AddDirectory("C:/");
+        filesystem.AddDirectory(dir);
+        var ds = new DirectoryService(Substitute.For<ILogger<DirectoryService>>(), filesystem);
+
+        Assert.Equal(DateTime.MaxValue, ds.GetLastWriteTime(dir));
+    }
+
+    #endregion
 }