Add support for sorting by json path in V3

[manasag]

This request was originally created here #2592 . This issue is to track this feature request in Hasura V3. Details:

The ability to sort the query results by a path of a JSON columns For example, for a table like

CREATE TABLE products (
  id serial NOT NULL PRIMARY KEY,
  translated_name jsonb NULL
);

I would like to have the ability to do something like

query productsSortedByName {
    products(order_by: {translated_name: {path: "en", how: asc_nulls_last}}) {
       id
       name: translated_name (path: "en")
   }
}

[CapCap]

This would be great as the whole point of json is dynamic data- your solution using native queries is no different than using a view in terms of end user experience, and as such is not a solution to the original problem.

[manasag]

Good news is that in V3 architecture, we have recently added support for nested filtering and ordering. While we currently are focusing on implementing these concepts for Mongodb as a priority; it paves the way to do the same with jsonb values with Postgres.