remote: allow get to retrieve OID-headed columns too
remote: allow get to retrieve OID-headed columns too

An OID-headed dense BAT is easy enough like a VOID-headed one.  Allow to
send such BAT.  Sloppily allow both VOID and OID-headed bats from
remote.get, since we can't know the target BAT is dense or not there.
Would basically require a fallback method instead of a-priori choice.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb