Provide a dialect option to not normalise booleans

[jakeng-grabtaxi]

Thanks for this amazing library.

Is your feature request related to a problem? Please describe.
I am trying to use this library to generate queries for Presto/Trino SQL. It seems that Trino does not support using IS when comparing bools, = should be used instead. Currently, the normalisation is "hardcoded" in

goqu/exp/bool.go

Line 157 in 21b6e6d

func checkBoolExpType(op BooleanOperation, lhs Expression, rhs interface{}, invert bool) BooleanExpression {

.

Describe the solution you'd like
I think there should be some way to specify (maybe at the dialect level) whether bools should be normalised. What you think?

Dialect

• trino/presto

Thanks!