Function queryProjectionRespectsGrouping

Verify that the projected variables (select head) respect the grouping of the query:

• no select * in a grouped query (GROUP BY, or a built-in aggregate in HAVING or ORDER BY)
• if grouped, selected variables need to be collected by the group-by, or bound by the trailing VALUES clause, which is joined after grouping (18.2.4.3). Section 11.4 only mentions the group-by variables, but the algebra of 18.2.4.3 binds the VALUES variables before the projection, as do the tests of https://github.com/w3c/rdf-tests/pull/383.
• if grouped, select expressions may use variables bound by preceding (expr AS ?var) expressions, as https://www.w3.org/TR/sparql12-query/#aggregateRestrictions allows (https://github.com/w3c/sparql-query/pull/380). Ungrouped queries always allow them (https://www.w3.org/TR/sparql11-query/#selectExpressions), but the SPARQL 1.1 text for grouped queries (https://www.w3.org/TR/sparql11-query/#aggregateRestrictions) does not, so ProjectionValidationOptions.rejectGroupedSelectAliasReuse rejects them. Function calls only group the query when ProjectionValidationOptions.namedAggregatorCallback decides they are custom aggregates, as they do in the algebra.