* tighten up checks for order by expressions fixed ordering by expressions
* added testing to cover order by cases
* Add DecimalAgg member to proto GroupCount definition
In DAX, where we have split the orchestrator from the executor, and the
orchestrator can run on a different host, there are cases where
`GroupCount`s can travel over the wire via the Internal Client. In these
cases, when the group count contains a decimal aggregate, we need to
send that value as the appropriate type.
* fixed missing cases in order by and case block eval
Co-authored-by: Travis Turner <travis@molecula.com>
(cherry picked from commit 158cc669d9)
