Use tokenProcessor for domain tokens
We currently support domain tokens in the
tokenCompatSubscriber - that class is 'really' about contact tokens & I'm inclined to think a tidy up of domain tokens would put them in their own class.
The question I have is 'what does it listen to' / when is it 'active' - ie when
listTokens is called I'm inclined to think domain tokens should be 'always returned' but the alternative is to listen for the schema
(currently they are returned whenever 'mailingTokens' is called plus a couple of other places)