CLN/BUG: array_equivalent on nested objects
5/5

The included code check won't pass until the others in this sequence are merged.
reverted the code check since one of the other PRs in this sequence is in a holding pattern.  this should now be straightforward @jreback gentle ping.  there is at least one more Exception we'll be able to get rid of once the array_equivalent bug here is fixed cool thanks @jbrockmendel 