Support label: modifier in search syntax

Bitbucket Server and Data Center 5.13 included the ability to set up to 5 labels per repo, as suggested in BSERV-2727. This is great, but the user has to go into a repo and click on a label link to see repos with that label.

Here are are some proposals for how this could work.

• Core feature
  • Users should be able to use a label: search modifier to perform more fine-grained searches than the label links provide. This would allow searching on files with certain extensions, but only in repos that contain one ore more specified labels.
• Sub-feature 1: Compact syntax
  • Further, it would be ideal to have a compact syntax to search through multiple labels, such as label:(prod OR docker) instead of having to use label:prod OR label:docker.
• Sub-feature 2: Wildcard support
  • With only five labels available, users may try to combine multiple aspects into a single label, such as prod_docker or prod_selenium, so being able to search for prod_* might be useful for really large repositories. Regular expressions are probably not totally necessary, and would add complexity, so this would be out of scope.

Fellow users, please vote if you'd like to have this, and feel free to suggest modifications to what I've proposed.