create MemoryGameBoardStore Class and rework Building of Game Board Storage

server/game_board_stats/__init__.py

@@ -0,0 +1,10 @@
+from server.game_board_stats.MemoryGameBoardStore import MemoryGameBoardStore
+from server.game_board_stats.RedisGameBoardStore import RedisGameBoardStore
+
+class GameBoardStoreBuilder:
+  @classmethod
+  def build(self, backend:str="memory", **kwargs) -> MemoryGameBoardStore|RedisGameBoardStore:
+    selected = (backend or "memory").strip().lower()
+    if selected == "redis":
+      return RedisGameBoardStore(**kwargs)
+    return MemoryGameBoardStore(**kwargs)