GPIO: add 26? use same GPIO for 2 bands?

[penfold42]

First up, great project - I've had a lot of fun working on a setup over the last few days.

Under Setup->Pi I/O:

1. Can we add GPO 26 to the webUI ?

2. Can we allow multiple bands to share a GPIO?
   I have one of those cheap relay controlled 4 band LPF from aliexpress and it uses the same LC bank for 15m and 10m.
   I know I can bodge it with a couple of diodes but if its easy, the webUI seems "nicer"

Thanks!

[lbussy]

Moved to #348 in WsprryPi Core.