[Jenkins][ci skip] Add check slave online status to watchdog
Merge pull request #6808 from Mazyod/cleanup-2d-platform

Cleanup 2d/platform library references
Merge pull request #6818 from lmskater/add-watch-slave-offline

[Jenkins][ci skip] Add check slave online status to watchdog
Release Notes for v3.1
Merge pull request #6821 from ricardoquesada/release_notes_3_1

Release Notes for v3.1