Issue Edit/Update
Created by: sunzoje
Is your feature request related to a problem? Please describe. Right now there's no way to update or edit issue for title, description, labels and others.
Describe the solution you'd like
Allow command to edit/update an issue:
glab issue update <issue_no> --label <newlabel>
for adding label.
Likewise we can have --unlabel <oldlabel>
to remove label