Build a proof of concept for an executable called mqlrun. The executable accepts the following:

• A set of input documents, probably encoded as a BSON file.
• An input query, probably expressed as JSON or extended JSON (or BSON?). Only need to support aggregation (not find, update, or other pieces of MQL).

mqlrun uses the server's implementation of the aggregation execution system to output the result set after running the agg over the input documents.

$lookup/$graphLookup are out of scope, as are the metadata sources like $collStats, $indexStats, etc. I think text search and geoNear should be out of scope as well.

POC consists of the following work items:

• Make a branch available for the POC in a fork of mongodb/mongo.
• Build a new executable which depends only on the base/bson libraries and the appropriate execution libraries.
• Make a new agg data source for scanning the input BSON file.