Issue #2005546 by mdrummond, joelpittet, Manuel Garcia, lauriii, lokapujya, epari.siva, hosef, rpayanm, emma.maria, HOG, zetagraph, wmortada, rteijeiro, Cottser, hussainweb, madhavvyas: Use branding block in place of page template branding variables (site name, slogan, site logo)

Issue #2470807 by LewisNyman, Dom., davidhernandez, emma.maria, lauriii, jp.stacey: Rename the default "Messages" region for all themes to "Highlighted"

Revert "Issue #2470807 by LewisNyman, Dom., davidhernandez, emma.maria, jp.stacey, lauriii: Rename the default "Messages" region for all themes to "Highlighted""

This reverts commit 249e520b.

Issue #2470807 by LewisNyman, Dom., davidhernandez, emma.maria, jp.stacey, lauriii: Rename the default "Messages" region for all themes to "Highlighted"

Issue #2289917 by Wim Leers, mdrummond, lauriii, Manuel Garcia, emma.maria, Scionar, davidhernandez: Convert "messages" page element into blocks