Provide SqlAdvisor via JDBC interface

Here's implementation of `SqlAdvisor` via table function available via JDBC as discussed in #151.
The function is not registered by default, the caller should include it to the desired schema.

PS. I do not like the way `SqlValidatorImpl#findAllValidUdfNames`: it asks all the object names in schema, then filters via `if (objName.getType() == SqlMonikerType.FUNCTION) {`, however that can be addressed separately.