Changing threading implementation

[JackNewman12]

Original feature just splits the database (containing the serial port + current status) and the combines it again once the threads are complete.

Task is to change it so that each thread takes the serial port permanently and pushes the status results to a mpsc. The receiver thread can then push the changes to the status dict (and maybe also trigger a websocket push once its implemented).

This should make it a little easier to recreate serial devices if something goes wrong with them (im looking at you windows) and means we can just poll the PSUs as fast as possible without hurting the web interface speed.