[Feature Request] arc sync from a branch - setting the current branch as default

[andreaschrader]

Is your feature request related to a problem? Please describe.
When using arc sync from a branch this requires always to add -b . This deviates from the github routines and ,therefore, it can well happen accidentally, that you forget to add -b . As a consequence, main is used as the default, the changes on the branch are pushed into main and the local branch is also switched to main. Again you might not realize this as you did not switch to main yourself. Eventually this causes merge conflicts.

Describe the solution you'd like
using the new branch from which the user executes arc sync as the default at least when it was used once with the -b option and the branch is also present already on remote.

Describe alternatives you've considered
Add warnings to the Arc Commander manual if this can not be changed.