sql: extend the logic test coverage

[knz]

In the wake of #7202 @petermattis suggests to revisit the following comment in sql/logic_test.go pertaining to the bigtest:

// TODO(pmattis): We don't support aggregate functions.
// logicTestPath + "/test/random/expr/*.test",
// TODO(pmattis): We don't support tables without primary keys.
// logicTestPath + "/test/select*.test",
// TODO(pmattis): We don't support views.
// logicTestPath + "/test/index/view/*/*.test",
// TODO(pmattis): We don't support joins.
// [uses joins] logicTestPath + "/test/index/random/*/*.test",
// [uses joins] logicTestPath + "/test/random/aggregates/*.test",
// [uses joins] logicTestPath + "/test/random/groupby/*.test",
// [uses joins] logicTestPath + "/test/random/select/*.test",

[knz]

This is a dup of #3292.