[PARKED:] feat: infer function types

[BobdenOs]

Description

Provide an infer function for each cql function. Which checks the inferred type of the arguments and returns the correlating return type.

Blocker

Infer does not infer the where clause of SELECT queries. cqn4sql does traverse all func tokens, but only provide the element property to tokens part of the root query elements.

cdsTypes seems like it should refer to cds.builtin.types ?