Support arbitrary composite access expressions

[ayman-sigma]

Right now the CompositeAccess expression is limited to support the PostgreSQL syntax like SELECT (on_hand.item).name FROM on_hand WHERE (on_hand.item).price > 9.
This PR generalize it to support arbitrary composite access expressions. CompositeAccess expression is any prefix expression followed by a period then an identifier. The CompositeAccess itself can also be nested.

This change fixes issues with dialects that can access fields from another expression. For example dialects that supports struct literal. Something like SELECT struct(1 as a).a wouldn't work before this PR.