This way elements can handle their logic themselves without having to
rely on outside utility classes.

Also restructure files in common in a more logical way.

- upgrade @ngx-translate/core
- upgrade rxjs
- upgrade testcafe

- run npm update

- Fix type of selectedGroup

- Expand the list of elements zo sanitize to
['text-field', 'text-area', 'text-field-simple', 'spell-correct']
- Rename sanitize method
- Change expectations in tests