BETA: further diminish redundant code

Next to an easier versioning, this is an attempt to further cut unnecessary/unused code, in trying to delete as many remnants of the old 'States' version as possible.

Please be aware for possible errors, and report issues if they arise. Also, please have a look if you spot further code to be deleted ;-)
installation:

- url: /local/lovelace/resources/custom-ui/custom-ui-beta.js?v=20210323-BETA
  type: module