[BUG] Release sql-plugin and udf examples jars

[tgravescs]

Describe the bug
If people want to use the RapidsUDF functionality we should be releasing the sql-plugin jar so they can put it as a dependency in their project. Also the udf examples jar shouold be released if people are expected to just use the examples we provide in there.

Also we should have a test that what we release actually works. Perhaps we need to split that into separate issue.

[jlowe]

Is it necessary to release the sql-plugin jar to access RapidsUDF? It is available in the existing RAPIDS Accelerator distribution jar:

$ jar tvf dist/target/rapids-4-spark_2.12-21.10.0-SNAPSHOT.jar | grep RapidsUDF
   207 Wed Oct 27 08:01:46 CDT 2021 com/nvidia/spark/RapidsUDF.class

Personally I'd rather have them depend on and compile against the same jar they're going to use at runtime if possible.

[tgravescs]

that's true, they should be able to use that, we should update our examples then to use it as well to make sure nothing was missed being made public

[jlowe]

The udf-examples jar should be published as part of moving it to a separate repo to fix #3971. As for the sql-plugin, I think we agree that doesn't need to be published since it's public APIs should be available via the dist jar and users should depend on that directly.