Add options to format identifiers (functions, properties)

[bitner]

Prototype to allow passing in a json whitelist or a function taking an input identifier string and returning the appropriate SQL.

[bitner]

@gadomski putting this up more of a prototype to figure out the right API that we want to use for this.

[gadomski]

Makes sense to me as a low-level, but we'll want some sort of "resolver generator" for the most common patterns?

let options = DuckDbOptionsBuilder::new().struct_field("assets").build();
expr.to_ducksql_with_options(options);

The resolver would then do whatever transformations necessary to turn properties that start with assets into the appropriately-quoted dot notation.