Add commit SHA to the nightly builds

[Utumno]

Doesn't need to be the full sha ten chars should be enough - helpful to track where a nightly was built from since we (wisely) stopped pushing the build commit to nightly.

[Infernio]

Definitely a good idea. Note the comment though:

wrye-bash/Mopy/bash/bass.py

Line 40 in 8a11027

AppVersion = '313' # must represent a valid float

Some scripts rely on this for sure, not sure what else does. It might be best to create a new app_version_extra string constant and format with that, like this:

f'{bass.AppVersion}-{bass.app_version_extra}'

Then log that in the BashBugDump instead of bare AppVersion, same with the title bar. Would also let us easily add RC1 etc. to release candidates.

Or maybe do the formatting right in bass? Not sure what's better.