Refactor utility-skip/extn-check code
Refactor utility-skip/extn-check code

This was getting pretty long and complex in the context of the main
utility hook. Moved out the checks for what should skip Citus process-
ing and what should have version checks performed.

citusdata/citus,citusdata/citus,citusdata/citus,citusdata/citus,citusdata/citus