Recently Added Chapter Feedback (#1020)

* Added an alt implementation which shows Recently Added chapters. No extra grouping is performed if multiple chapters per volume.

* Started working on a grouping implementation for series.

* Disabled the code for bookmarks cleanup as there is some critical issue in there.

* Implemented a Series Group activity stream which shows recently updated series and providers a count badge showing how many new chapters/volumes were added in that series.

* Removed the bookmark disabling code

* Cleaned up code

* One more code cleanup

API/DTOs/GroupedSeriesDto.cs

@@ -0,0 +1,32 @@
+using System;
+using API.Entities.Enums;
+
+namespace API.DTOs;
+/// <summary>
+/// This is a representation of a Series with some amount of underlying files within it. This is used for Recently Updated Series section
+/// </summary>
+public class GroupedSeriesDto
+{
+    public string SeriesName { get; set; }
+    public int SeriesId { get; set; }
+    public int LibraryId { get; set; }
+    public LibraryType LibraryType { get; set; }
+    public DateTime Created { get; set; }
+    /// <summary>
+    /// Chapter Id if this is a chapter. Not guaranteed to be set.
+    /// </summary>
+    public int ChapterId { get; set; } = 0;
+    /// <summary>
+    /// Volume Id if this is a chapter. Not guaranteed to be set.
+    /// </summary>
+    public int VolumeId { get; set; } = 0;
+    /// <summary>
+    /// This is used only on the UI. It is just index of being added.
+    /// </summary>
+    public int Id { get; set; }
+    public MangaFormat Format { get; set; }
+    /// <summary>
+    /// Number of items that are updated. This provides a sort of grouping when multiple chapters are added per Volume/Series
+    /// </summary>
+    public int Count { get; set; }
+}