[SPARK-18752][HIVE] isSrcLocal" value should be set from user query.

The value of the "isSrcLocal" parameter passed to Hive's loadTable and
loadPartition methods needs to be set according to the user query (e.g.
"LOAD DATA LOCAL"), and not the current code that tries to guess what
it should be.

For existing versions of Hive the current behavior is probably ok, but
some recent changes in the Hive code changed the semantics slightly,
making code that sets "isSrcLocal" to "true" incorrectly to do the
wrong thing. It would end up moving the parent directory of the files
into the final location, instead of the file themselves, resulting
in a table that cannot be read.

I modified HiveCommandSuite so that existing "LOAD DATA" tests are run
both in local and non-local mode, since the semantics are slightly different.
The tests include a few new checks to make sure the semantics follow
what Hive describes in its documentation.

Tested with existing unit tests and also ran some Hive integration tests
with a version of Hive containing the changes that surfaced the problem.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #16179 from vanzin/SPARK-18752.