Exploit tensor structure in quadrature rules

This selects reduced quadrature orders for geometries with tensor structure:

The QuadratureRuleKey order k indicates polynomials of degree atmost k. As an exception, for reference polyhedrals with a tensor structure, polynomials with coresponding tensor structure of degree at most k for each tensor direction are now also allowed. E.g. bi-cubic polynomials on a square are encoded as order 2 (altough they are polynomials of degree 4).

Notice that this also changes the rules for derivatives: In the tensor case the order is usually kept as is. Thus we now have order k instead of (k*d)-1 for the derivative in this case.