We should scrub out the remaining few users of the following APIs so that they can be removed:

• BSONForEach — Replace with range-for loop
• BSONObjIterator::moreWithEoo() — Use more() and remove if (e.eoo()) break;. Consider rewriting to use range-for loop.
• BSONObj::getObjectId — Use if (auto id = obj["_id"]; id) {...}
• BSONObj::removeFields(std::set<std::string>) — Use the StringDataSet overload instead.