[YCQL] Check support for OFFSET with aggregates (like MIN)

[pkj415]

Jira Link: DB-4302

Description

We allow OFFSET in SELECT queries in YCQL, but apache cassandra doesn't (https://cassandra.apache.org/doc/latest/cassandra/cql/dml.html)

Given this, did we intend to support aggregates queries like MIN with OFFSET?

If we did, check if it works correctly and add tests. If not, ensure that it errors out explicitly.

[OlegLoginov]

OFFSET can be useful for an aggregate function like AVG or MIN if you want to get a result for a random subset of rows.
E.g. for 1 or for a few tablets.
That's why I've not disabled OFFSET for aggregate functions.
(In the fix for #13295.)