Reformulate StatementContextFactory.createEffective()

Rather than passing down StmtContext and its parent via StmtContext.getParent() we want to be in control of what gets accessed during statement build phase.

The core contract is StatementContextFactory, which will need two replacement interfaces, and the primary implementation is StatementContextBase.

We then need to audit all subclasses of StatementContextBase and migrate their accesses to the new interfaces.

InferredStatement context plays a role here in that will plugin into these interfaces with methods which do not force memoized materialization in StatementContextBase