PgJQ: Use Jq in Postgres SQL

I recently ported some rather complex JQ programs to jsonb & jsonpath queries. After a while, it became too cumbersome, so I paused for a few days and developed this Postgres extension.

pgJQ embeds the standard jq compiler and brings the much-loved jq lang to Postgres.

It adds a jqprog data type to express jq programs and a jq(jsonb, jqprog) function to execute them on jsonb objects. It works seamlessly with standard jsonb functions, operators, and jsonpath.