Optimize statediff and fix hamt bug

[austinabell]

Summary of changes
Changes introduced in this pull request:

• Now the diff only shows the added, removed, or changed actor states instead of diffing the whole resolved and ordered (through BTreeMap) JSON state.
  • There was not a good reason to print out all other actors anyway, but this can be added if others want
  • It's basically instant now, and now usable on this much larger state
• Bug in hamt was in the case of one of the child nodes being a link, if the other values are less than the max array length, it would be pulled up and the link would be removed

syncing to epoch: 1442

Reference issue to close (if applicable)

Closes

Other information and links