Port to lgpio as a wiringPi replacement

[tomwardill]

wiringPi is deprecated and removed from the repos.
Also, it is not usable on a Pi5 due to the new GPIO chip and interface.

Instead, remove the use of wiringPi and use lgpio http://abyz.me.uk/lg/lgpio.html.
This allows use on bullseye, bookworm, and in theory, future releases.

• Convert the wiringPi calls
• Change the pin definitions to match the lgpio names instead of wiringPi
• Use lgpio compatible callbacks

Also, the paho mqtt library is now packaged in the repositories, so we can just install that and link against it, instead of building our own from source.

This has been lightly tested locally, and is recieving and parsing packets.
Apologies for the whitespace changes, my IDE got a bit carried away.