CC Synaxis Connector

Main changes:

• hub.set() / hub.write() now only validate and enqueue; they no longer access the world or Synaxis from the CC worker thread.
• Writes are executed by the server tick in FIFO order.
• At most 256 writes are executed per tick, and the queue holds at most 1024 entries, preventing control scripts from overloading a single tick.
• After deleting or replacing a port, old queued writes will not be mistakenly written to the new port.
• hub.refresh() has been changed to execute via a CC main-thread task.
• When an asynchronous write fails, a cc_synaxis_super_hub_write_failed event is sent, with the port name as the argument.
• The README has documented the new asynchronous write semantics. The key code is located in CCSynaxisSuperHubBlockEntity.java (line 278) and CCSynaxisSuperHubPeripheral.java (line 70).