Tune button doesn't toggle loaded tuning on Windows

[mkruselj]

Exactly as subject says.

[baconpaul]

So here’s how it works on Mac at head

with a tuning loaded the button toggles
If you toggle tuning on and choose standard tuning it is no longer toggleable

so I think what we need to do is - like I did with the rest of the tuning stack in 19 - write the state machine charefulky then see where I introduced the bug in the ui rewrite. Easy but requires a wee bit of caution since we need to deal with the rebuild and the non rebuild state