Bug fixes

Changed widget theming to support nexted display

• #2021649: Unable to save multiple parents to a term
• #2303443: Broken link "Disable Double Tree"

First Drupal 8/9 stable version!
Thanks everyone for contributing.

Issues included since last release.

Fixed issues:

• Drupal 9 compat for Token unit tests, thanks jaydub!
• Add method to retrieve Block Content, thanks Nuuou!
• Drupal 9 compat, thanks Ambient-Impact!
• Change ViewFieldEventVariables->getField return type, thanks Joris Handstanger!

Updated dev contrib and fixed multiple new found style & code problems.

Drupal 9 compatibility.

Drupal 9 compatibility.