Fix minor warnings in Emby.Server.Implementations (#2149)

Emby.Server.Implementations/Data/SynchronousMode.cs

@@ -0,0 +1,30 @@
+namespace Emby.Server.Implementations.Data;
+
+/// <summary>
+/// The disk synchronization mode, controls how aggressively SQLite will write data
+/// all the way out to physical storage.
+/// </summary>
+public enum SynchronousMode
+{
+    /// <summary>
+    /// SQLite continues without syncing as soon as it has handed data off to the operating system.
+    /// </summary>
+    Off = 0,
+
+    /// <summary>
+    /// SQLite database engine will still sync at the most critical moments.
+    /// </summary>
+    Normal = 1,
+
+    /// <summary>
+    /// SQLite database engine will use the xSync method of the VFS
+    /// to ensure that all content is safely written to the disk surface prior to continuing.
+    /// </summary>
+    Full = 2,
+
+    /// <summary>
+    /// EXTRA synchronous is like FULL with the addition that the directory containing a rollback journal
+    /// is synced after that journal is unlinked to commit a transaction in DELETE mode.
+    /// </summary>
+    Extra = 3
+}