Misc Bugfixes and Enhancements (#507)

* Removed some extra spam for the console

* Implemented the code to update RowVersion, which is our concurrency check

* Fixed a critical issue where more than one bookmark could occur for a given chapter due to a race condition. Now we use concurrency checks and we also gracefully allow more than one row, by only grabbing first.

* Cleaned up the logic for IHasConcurencyToken and updated the setters to be private.

* Lots of comments and when deleting a library, remove any user progress items for which chapters don't exist.

* When deleting a Series, cleanup user progress rows.

* Now after a scan of library, if a series is removed, collection tags are pruned as well if there are no longer any series bound to it.

* Updated the image on the Readme to show a better picture

* Small code cleanup to remove null check modifier as I check for null just before then

* Fixed images loading multiple times due to using function in binding with random. You can now click chapter images to read that chapter specifically.

* Fixed cards being different sizes when read vs unread

* Moved over Robbie's workflow changes from notifier. Commented out activity indicators as that is not shipping with this release.

* Remove code that isn't needed

* Reverted GA

* Changed GA to trigger only when HEAD is updated

API/Data/DataContext.cs

@@ -1,4 +1,7 @@
 using System;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using API.Entities;
 using API.Entities.Interfaces;
 using Microsoft.AspNetCore.Identity;
@@ -67,5 +70,48 @@ namespace API.Data
             if (e.NewState == EntityState.Modified && e.Entry.Entity is IEntityDate entity)
                 entity.LastModified = DateTime.Now;
         }
+
+        private void OnSaveChanges()
+        {
+            foreach (var saveEntity in ChangeTracker.Entries()
+                .Where(e => e.State == EntityState.Modified)
+                .Select(entry => entry.Entity)
+                .OfType<IHasConcurrencyToken>())
+            {
+                saveEntity.OnSavingChanges();
+            }
+        }
+
+        #region SaveChanges overrides
+
+        public override int SaveChanges()
+        {
+            this.OnSaveChanges();
+
+            return base.SaveChanges();
+        }
+
+        public override int SaveChanges(bool acceptAllChangesOnSuccess)
+        {
+            this.OnSaveChanges();
+
+            return base.SaveChanges(acceptAllChangesOnSuccess);
+        }
+
+        public override Task<int> SaveChangesAsync(bool acceptAllChangesOnSuccess, CancellationToken cancellationToken = default(CancellationToken))
+        {
+            this.OnSaveChanges();
+
+            return base.SaveChangesAsync(acceptAllChangesOnSuccess, cancellationToken);
+        }
+
+        public override Task<int> SaveChangesAsync(CancellationToken cancellationToken = default(CancellationToken))
+        {
+            this.OnSaveChanges();
+
+            return base.SaveChangesAsync(cancellationToken);
+        }
+
+        #endregion
     }
 }