Support for more JSON path functions

[kesavkolla]

Summary

In OLAP usecases data locality tkaes precedence over data normalization the usage of nested data is very common practice. People use arrays and arrays of structs to hold data together with main data.

Eg: If we need to design an account table with multiple addresses we create address as JSON and store array of address as JSON objects.

To better handle these nested datatypes specially list of structs we need a better JSON Path handling. PostgreSQL has functions like

jsonb_path_query_first
jsonb_path_query
jsonb_path_query_array

These type of functions will be useful for handling nested structures.

Integrating https://github.com/besok/jsonpath-rust library to expose these type functions will greatly help usability.