SQL: Fix issues with GROUP BY queries (#41964)

Translate to an agg query even if only literals are selected,
so that the correct number of rows is returned (number of buckets).

Fix issue with key only in GROUP BY (not in select) and WHERE clause:
Resolve aggregates and groupings based on the child plan which holds
the info info for all the fields of the underlying table.

Fixes: #41951
Fixes: #41413
(cherry picked from commit 45b85809)