Move doc info retreiving logic in open_doc's coordinator

Remove a separate coordinator for retreiving of doc info and move
the logic into fabric_doc_open.erl as the majority of functionality
is the same for both modules.
Add an option to filter out full info of the deleted docs

Selector of the record type moved into handle_response
to allow at least basic unit testing and consequently
adding an ability to filter out full_doc_info of the deleted docs.