Support wildcard in branch name

We have several requests from maintainers to support wildcards in branch name.
This feature need to be discussed first, as tracking such tree become a bit more complicated in kcidb.

Example: https://github.com/kernelci/kernelci-core/issues/2698

Start with this issue and the referenced KernelCI example at kernelci-core issue 2698; no implementation files or tests are identified in the payload. First clarify the wildcard branch-name semantics and how matching should be tracked in kcidb, then define the agreed behavior and its validation cases.

Written by the indexing model from the issue text.