Add safeguards to prevent NearStage from getting stuck

In SERVER-56928, an issue caused a $near query to get stuck by continually adding OrderedIntervals to 'NearStage::_childrenIntervals' until the server crashed with an OOM error. Though the root cause is known and a fix was merged, this sort of scenario could play out in the future with other geospatial query bugs. As such, we should add some sort of safeguard that could detect that the NearStage is making no progress and raise a Query fatal error (as opposed to allowing the query to run until an OOM error is raised and the server stops running).