feat: implement SortByInternalDifficulty

SortByInternalDifficulty/MU3.DB/patch_MusicSort1ID.cs

@@ -0,0 +1,19 @@
+using MonoMod;
+
+namespace MU3.DB;
+
+[MonoModPatch("global::MU3.DB.MusicSort1ID")]
+[MonoModEnumReplace()]
+public enum patch_MusicSort1ID {
+    Genre = 0,
+    All = 1,
+    Character = 2,
+    Version = 3,
+    Level = 4,
+    Name = 5,
+    Attribute = 6,
+    InternalLevel = 7,
+    Begin = 0,
+    End = 8,
+    Invalid = -1
+}