Remove concept, helpers and tests of accurate per-GI row counts
Bump data version
Minor cleanup
merge nathanlws: Remove group index row counters

Merge pull request #1237 from nathanlws/sql-layer/no-gi-row-counts
https://github.com/FoundationDB/sql-layer/pull/1237
Pull out a subclass so it can be used elsewhere.
Move non-group join conditions as well when possible.
Adjust some expected results.