The goal of this task is to add a new jstest with at least 50-100 testcases that test out different aggregate() pipelines with multiple $project stages / $addFields stages mixed with other interesting stages like $match, $group, and $lookup.

This new jstest should be placed somewhere within the jstests folder where it's guaranteed to run (1) with sbeFull enabled and forceClassic disabled, (2) with sbeFull disabled and forceClassic enabled, and (3) with default settings (sbeFull and forceClassic disabled).