Update jstests to verify that generated validation errors are propagated correctly under the 'errInfo' field for aggregates which use $out/$merge and for mapReduce commands.

It appears that 'jstests/core/bypass_doc_validation.js' already has coverage for $out and mapReduce, and separately jstests/aggregation/sources/merge/bypass_doc_validation.js already has coverage for $merge, so these tests should be extended to verify that the 'errInfo' field is propagated for each of the three operations.