GEOMESA-6 Secondary Indexing (PR for comments)

Starting this PR for comments contains code from GEOMESA-169 that will be removed after PRs 107,108 are merged. I'll squash things up later.

The table format changes. Each store has a "Catalog Table" to store feature metadata then three tables per SFT:
1. Attribute Index - Inverted attribute index of simple feature values
2. Record Table - Records only (contains rows referenced by inverted index)
3. ST Index - same as before (spatiotemporal index)

Only equalTo and like queries with trailing % should hit the attr index

AccumuloDataStore is backwards compatible with the old table format (only ST with metadata) and will respect that.

Other Notes:
* Haven't updated the GeoMesa pages yet for multiple tables...that'll come in the next PR

Please comment :)
We need to pre-split tables.  Probably for another ticket.  For the attribute index, we should split on attribute name (and eventually shard+attributeName).  For the record index, it's not clear - if we're using UUID, we can split based on hex digits.  Thoughts?