* define registry interface

* init in-memory registry

* remove ununsed variable, added comments

* add inmemory registry tests

* introduce DNSRecord struct

* use noop registry

* remove zone from registry fields

* replace provider with registry in controller

* move noop registry interface check to test

* remove ownerid from noop registry

* fix: remove dangling empty line

* return provider records directly with noop

* adjust according to pr review

* fix noop tests