Release notes/CHANGELOG for 12.2 (#3675)

* Changelog-release notes for 12.2

* Small additions

* Added sections below table

* Added doc note

* Removed old copy of changelog

* Fixes from review

* Updated dependencies table

* Added bug descriptions

* Added New Feature highlights

* Removed old metapackages section

* Removed some 12.1.0 metapackage info

* Updated Highlights section to include the deprecated GQL fields

* Added Venia sample data metapackage to the release notes

* Removed link to docs for sample data for now

* Branding fix

Co-authored-by: Bruce Denham <bdenham@adobe.com>

Author: dobooth