glab mr update <branch> Provide an option to select the state of the MR

Problem to solve

Currently glab mr update <branch> searches for MR for the branch in ANY state.

This is inconsistent with the defaults for mr list and mr merge which only search for opened MRs.

Proposal

It would be nice to have an option for the state of the MR. For example I only want to search for opened MRs.

Further details

This behavior is inconsistent with the behavior of GitHub's CLI and causes problems when porting workflows.

Links / references