Visitors Produce "Invalid" Trees

[jack-gitdev]

Some visitors trigger on the presence of a reference node sitting behind a reference expression.
Some visitors add a double parenthesis but drop a reference node

((FOO == 'bar'))
Expected: ref -> refExp -> ref -> refExp
Actual: refExp -> ref -> refExp

Validate that query trees do not produce doubley wrapped nodes (double parenthesis) and each parenthesis (reference expression) should have a parent that is a reference node.

[d-hwang]

I believe this ticket is related to #1235

[jack-gitdev]

This may also be related #1165