Can't do full width alignment - alignWide is ignored

Problem/Motivation

Since upgrading to 3, there is no way to set blocks wide or full width. Putting 'alignWide: true' in the *.gutenberg.yaml does not do anything. It used to be available by default.

Steps to reproduce

Add this to gutenberg YAML:

theme-support:
alignWide: TRUE

Proposed resolution

Have the editor settings respect the alignWide setting, and preferably default as we did before to alignWide: TRUE regardless.