BREAKING CHANGE: The MongoDB aggregation pipeline requires native MongoDB syntax instead of the custom Parse Server syntax; for example pipeline stage names require a leading dollar sign like `$match` and the MongoDB document ID is referenced using `_id` instead of `objectId` (#8362)
* add search for atlas search index
* added test for search in pipeline
* removed stage name check in pipeline
* removed spec for invalid query invalid key
* updated changelog
Co-authored-by: Diamond Lewis <findlewis@gmail.com>