format-table: add new helper table_print_with_pager()

format-table: add new helper table_print_with_pager()

This adds a new function table_print_with_pager() which is a wrapper
around table_print_json()/table_print() but spawns a pager first, if
that's enabled, and optionally turns off the header line of the table.

This addresses the fact that many of our tools actually keep doing very
this very similar stuff, over and over again. Let's unify this in one
place.