Custom Operator to accept Record as input

I really liked the Json Rules Engine. It would be good if record object is also pushed as input to operator so that one can compare relative value from the same Record using Json Path by introducing custom Operator in the engine. At present, there is not way to have Record object as operator input.

No file or test is named. Start by locating the custom-operator evaluation path and how its current input is constructed. Done means a custom operator can receive the Record object and compare values from that same record through Json Path, with coverage for the behavior.

Written by the indexing model from the issue text.