Leverage EntityUpdate API

• wait for this drupal core issue to be solved

Changes to geek-merlin include:

• Allow it to work with existing users
• no unneccesary update hook
• don't make changed revisionable (for now)
• Correctly name user revision tables
• in install hook, check that it's actually a BaseFieldDefinition when trying to call setRevisionable()

closes #3197068

config/schema/user_revision.schema.yml

+user_revision.settings:
+  type: config_object
+  label: 'user_revision Settings'
+  mapping:
+    user_revision_always_enabled:
+      type: boolean
+      label: 'user_revision_always_enabled'
+    user_revision_default_enabled:
+      type: boolean
+      label: 'user_revision_default_enabled'
+    user_revision_default_open:
+      type: boolean
+      label: 'user_revision_default_open'
+    user_revision_user_log_enabled:
+      type: boolean
+      label: 'user_revision_user_log_enabled'