Remove stale test
Clean up test-select.yaml
Add DECIMAL UNSIGNED to DECIMAL cast.

Remove indirect cast path from DECIMAL UNSIGNED to float, dobule.
Add indexes to types_i used by test-select
merge nathanlws: Add cast from DECIMAL UNSIGNED to DECIMAL

Merge pull request #1575 from nathanlws/sql-layer/fix-decimal-unsigned-cast
https://github.com/FoundationDB/sql-layer/pull/1575