DRILL-5318: Sub-operator test fixture
This commit depends on:
* DRILL-5323
This PR cannot be accepted (or built) until the above are pulled and
this PR is rebased on top of them. The PR is issued now so that reviews
can be done in parallel.
Provides the following:
* A new OperatorFixture to set up all the objects needed to test at the
sub-operator level. This relies on the refactoring to create the
required interfaces.
* Pulls the config builder code out of the cluster fixture builder so
that configs can be build for sub-operator tests.
* Modifies the QueryBuilder test tool to run a query and get back one
of the new row set objects to allow direct inspection of data returned
from a query.
* Modifies the cluster fixture to create a JDBC connection to the test
cluster. (Use requires putting the Drill JDBC project on the test class
path since exec does not depend on JDBC.)
Created a common subclass for the cluster and operator fixtures to
abstract out the allocator and config. Also provides temp directory
support to the operator fixture.
Merged with DRILL-5415 (Improve Fixture Builder to configure client
properties)
Moved row set tests here from DRILL-5323 so that DRILL-5323 is self
contained. (The tests depend on the fixtures defined here.)
Added comments where needed.
Puts code back as it was prior to a code review comment. The code is
redundant, but necessarily so due to code which is specific to several
primitive types.
closes #788
