Add JsonB Operators to Agtype

[JoshInnis]

Add JsonB Operators from Postgres to Agtype and allow in the Cypher command.

Initial Discussion
#199

Postgres JsonB Operator Documentation:
https://www.postgresql.org/docs/11/functions-json.html

[JoshInnis]

Add JsonB Operators from Postgres to Agtype and the Cypher Grammar

[JoshInnis]

Status: Formatting Issues, to be rebased for both Postgres 11 and 12 versions.