Add migration hook to remove empty config and unneeded dependency

Problem/Motivation

#3331366: Remove epp default dependency in all fields config sync files corrects the creation of 'empty' EPP config data and unneeded dependency. Now we need to clean up existing 'empty' data, eg:

dependencies:
  ...
  module:
    - epp
  ...
third_party_settings:
  epp:
    value: ''
    on_update: 0

Proposed resolution

Implement an update hook to remove EPP third_party_settings and dependency where both value and on_update are empty/false in field config items.