LttPClient: add snes write command

LttPClient.py

@@ -80,6 +80,18 @@ class LttPCommandProcessor(ClientCommandProcessor):
         else:
             return False
 
+    def _cmd_snes_write(self, address, data):
+        """Write the specified byte (base10) to the SNES' memory address (base16)."""
+        if self.ctx.snes_state != SNESState.SNES_ATTACHED:
+            self.output("No attached SNES Device.")
+            return False
+
+        snes_buffered_write(self.ctx, int(address, 16), bytes([int(data)]))
+        asyncio.create_task(snes_flush_writes(self.ctx))
+        self.output("Data Sent")
+        return True
+
+
 class Context(CommonContext):
     command_processor = LttPCommandProcessor
     game = "A Link to the Past"