This PR is meant to get all columns from an index
based on the TrackExistence row.
`All()` is a PQL function that can be used as a typical
row object. Optional arguments are `limit` and `offset`.
In order to standardize results as streams of RowResponse,
this PR introduces two interfaces `StreamClient` and
`StreamServer`) which mirror the grpc stream interfaces.
Upstream users (sqlmapper, vdsm, etc) can implement
instances of these interfaces to ensure that results can
stream through the entire sytem in an expected way.
This PR also fixes a couple of missing data types.
add makeRows() tests
register the gRPC server
use api.Index() instead of api.Schema()
support most field types in Inspect() query
currently, there's no support for `time` fields.
those will be dependent upon the output format
and the ability to materialize the timestamp from
the time views.
this commit also changes the response type of the
`Inspect()` query to be a tabular `RowResponse`.
