### What changes were proposed in this pull request?
This PR aims to add tag `ExtendedSQLTest` for `SQLQueryTestSuite`.
This doesn't affect our Jenkins test coverage.
Instead, this tag gives us an ability to parallelize them by splitting this test suite and the other suites.
### Why are the changes needed?
`SQLQueryTestSuite` takes 45 mins alone because it has many SQL scripts to run.
<img width="906" alt="time" src="https://user-images.githubusercontent.com/9700541/65353553-4af0f100-dba2-11e9-9f2f-386742d28f92.png">
### Does this PR introduce any user-facing change?
No.
### How was this patch tested?
```
build/sbt "sql/test-only *.SQLQueryTestSuite" -Dtest.exclude.tags=org.apache.spark.tags.ExtendedSQLTest
...
[info] SQLQueryTestSuite:
[info] ScalaTest
[info] Run completed in 3 seconds, 147 milliseconds.
[info] Total number of tests run: 0
[info] Suites: completed 1, aborted 0
[info] Tests: succeeded 0, failed 0, canceled 0, ignored 0, pending 0
[info] No tests were executed.
[info] Passed: Total 0, Failed 0, Errors 0, Passed 0
[success] Total time: 22 s, completed Sep 20, 2019 12:23:13 PM
```
Closes#25872 from dongjoon-hyun/SPARK-29191.
Authored-by: Dongjoon Hyun <dhyun@apple.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
76bc9db749
