add reset and boot loader key codes to bt layer (on thumb keys)

[mcrosson]

this PR adds reset and boot loader key codes to the big ardux layout

this may or may not be desired by the community and i wanted to be sure it was available if there is an interest

[granitrocky]

This seems like a solid change that doesn't impact other functions.
Looks like it's only on the big layer, and those keys are unused by default.

Could you do me a favor and rebase your commits to the main branch?
I can do a squash merge when I apply the PR.

[mcrosson]

Rebased and re-pushed based on latest zmk-ardux main branch. This should be good to merge.