Adds a method for printing active release trains for a configured project. This is helpful for the release tool that will print the active release trains. Also this can be useful for the caretaker status command, where we could print the active version branches (i.e. "is there currently a feature-freeze branch"). PR Close #38656
Versioning for the Angular organization
The folder contains common tooling needed for implementing the versioning as proposed by this design document. Primary tooling is the determination of active release trains.