Allow wildcard in default branch for repository config

For the repository configuration of "default branch", at the moment you can only select existing branches from the drop down list.

I propose it be a free-form text field, which allows wildcards. For example, we create multiple release branches each sprint, such as: release/xyz-123 release/zya-523 ... and so on...

So it would be really helpful to set the default branch as "release/*" or something similar. If there are multiple found, then any logic would be fine such as oldest existing or first one in the query, etc. I would expect it up to the repository maintainers to avoid such a scenario.

Thanks