REGTESTS: stick-table: read the counters through sc1_ and sc2_ as well

REGTESTS: stick-table: read the counters through sc1_ and sc2_ as well

The sc1_* and sc2_* families are pure aliases of the sc0_* ones with a
different hard-coded stick counter id, and none of their 29 entries was
covered. The notes listed extending this test as the way to close them
all at once, which is what this does.

Two more tables are added, one per extra stick counter, rather than
tracking the single existing one three times, which would have counted
every connection and every request three times and forced all the
existing values to be rewritten. Each counter therefore sees its own
copy of the same entry, and the sc1_ and sc2_ readings are compared to
the sc0_ ones rather than to hard-coded values. The generic form with
the ids 1 and 2 is read the same way.

sc0_bytes_in_rate and sc0_bytes_out_rate, which the first version had
missed, and src_updt_conn_cnt(), which creates its entry as it reads it
and therefore gets a table of its own, are covered too.