Remove references to instance count properties in Context/QueryForm

These fields(count, distinct_count, record_count) have been removed in
Avocado but were still being assigned here. These assignments made no
sense given that these names are now bound methods in Avocado and that
they won't be returned by endpoints during serialization anyway. If it
is the counts someone is after, they can use the ContextStats and
QueryStats endpoints to get that info.

Signed-off-by: Don Naegely <naegelyd@gmail.com>