Give editors ability to assign contributor, blogger roles & managers all roles

(short of administrator, which did require doing each role individually rather than 'all roles'
despite issues which suggested it wouldn't do the administrator.)

Ref #78

config/sync/core.extension.yml

@@ -93,6 +93,7 @@ module:
   rdf: 0
   redirect: 0
   responsive_image: 0
+  role_delegation: 0
   scn: 0
   search_api: 0
   search_api_db: 0