refactor: reorganize networking and data bridge scenes

* Move networking scenes under `controllers/networking`
* Move data bridge scene under `scenes/data`
* Rename the bridge node to `data_bridge`
* Update lobby UI scene path
* Remove unused lobby RPC node/script

controllers/networking/game_server.gd

@@ -0,0 +1,31 @@
+class_name GameServer extends ServerNetworking
+
+
+func _ready() -> void:
+	setup_signals()
+
+
+func setup_signals() -> void:
+	pass
+
+func server_client_connected(id: int) -> void:
+	push_warning("Client Connected... ID: ", id)
+
+	if not Globals.game_data.client1:
+		Globals.game_data.client1 = id
+	elif not Globals.game_data.client2:
+		Globals.game_data.client2 = id
+
+	if Globals.game_data.client1 and Globals.game_data.client2:
+		Globals.multiplayer_data.init_match()
+
+	# TODO: Add watch match feature...
+
+func server_client_disconnected(id: int) -> void:
+	push_warning("Client Disconnected... ID: ", id)
+
+	MessageBus.emit_propagation_clients_only.rpc("game_peer_disconnected", null)
+
+	await get_tree().create_timer(5.0).timeout
+	# NOTE: Quits game server instance.
+	get_tree().quit()