Arcade: [darc/maestro++] Normalize branch names

[JohnTortugo]

We need to add branch names validation in a few places in the Maestro API to prevent users from inserting "invalid names". Valid branch names should match the format used by $(Build.SourceBranch) AzDO variable.

/cc @riarenas @mmitche

[mmitche]

@JohnTortugo Do you mean forgetting the refs/heads bit for default channels, or entering a truly invalid git branch name?

[JohnTortugo]

Yeah, just missing the "refs/heads" part

[mmitche]

I think we should just normalize the inputs, rather than rejecting requests without it. The refs/heads bit isn't that interesting from a user's perspective.

[riarenas]

I was actually looking for an issue I thought I created about normalizing the branch names throughout the API, but I guess I never opened it. I agree we should just normalize.

[JohnTortugo]

Yeah, normalizing is fine. At the end my point was really to maintain a consistent format all around in BAR.

[JohnTortugo]

This was hit again twice by a user.