tests: publish extract_paging_state and count_rows_fetched
tests: publish extract_paging_state and count_rows_fetched

These local lambda functions will be reused, so they are promoted
to static functions.

avikivity/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,avikivity/scylla