Indicate that "git.branchProtectionPrompt: alwaysCommitToNewBranch" is active

[hediet]

Testing #150723

When git.branchProtectionPrompt is set to "alwaysCommitToNewBranch", and committing on a protected branch, it is hard to figure out what is going on if you don't know about protected branches.

The branch prompt should contain a message why the user is prompted to enter a branch name.
Alternatively, there should be an indication before committing that the user is committing to a protected branch.

[joaomoreno]

Same as #151053 IMO.

[lszomoru]

Correct. Closing as duplicate of #151053.