Help: Add missing version and cross-reference details for test measurements and labels
!6192 (merged), !6204 (merged) and !6234 (merged) added new features related to additional test measurements and test labels. The docs for those were missing versionadded
details, so add them now. Those merge requests also added support for adding labels dynamically to a test during execution. The docs lacked sufficient cross-referencing of related features in some places, so address that too.
Backport: release