Nanotrasen Block Game is here (#2131)

* tetris!

* softdropping & left,right key holding

* started work on the ui

* playable state

* there you go exp

* multiuser rework

* ui update refactor

* blockgame™️

* highscores, keybindings, ui refactor

* speed adjusts
leveling

* highscorebackground tweak
speed tweak

* NULLABLE

* yes

Content.Shared/Arcade/BlockGamePlayerAction.cs

@@ -0,0 +1,24 @@
+using System;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Arcade
+{
+    [Serializable, NetSerializable]
+    public enum BlockGamePlayerAction
+    {
+        NewGame,
+        StartLeft,
+        EndLeft,
+        StartRight,
+        EndRight,
+        Rotate,
+        CounterRotate,
+        SoftdropStart,
+        SoftdropEnd,
+        Harddrop,
+        Pause,
+        Unpause,
+        Hold,
+        ShowHighscores
+    }
+}