Allow for using latest tag with wildcard pattern as the referenceBranch

[piotrgwiazda]

Use case:
In a CI/CD pipeline, I'd like to build differences compared to a last successful build (rather than just HEAD~1) to avoid a situation of building a difference based on an unstable version.

• Each build leaves a tag e.g. build-1234, build-1235,
• I'd like to use something like referenceBranch=/refs/tags/build-*

Workarounds:

• Each build can leave another tag e.g. "latest-build" and then referenceBranch=/refs/tags/latest-build. The problem is that the build agent must have a force push permission which I'd like to avoid.
• Rather than using a tag, each build could fast-forward merge into a special "last-build" branch. Logically it should be tagging operation rather than branching...