When building the environment stamp, support two modes: release and snapshot
The release mode will always stamp using the current version of in the root package.json
and in snapshot mode will use a version stamp expressing a version based on the tag and
the number of commits from the tag.
PR Close#40095
Moves the existing `ng-dev release env-stamp` command into a
subfolder so that the staging/publish tool can have its own
dedicated folder (without being polluted by the env-stamp logic).
Every subcommand should be in its own folder.
PR Close#38656