[FEA] Move udf-examples to spark-rapids-examples

[res-life]

Is your feature request related to a problem? Please describe.
We cannot fully test the UDF interface is working correctly without an external project. Otherwise we risk tying the udf-examples build to the rapids-4-spark build, and that is very problematic (and triggered the desire to move this out in the first place).

Describe the solution you'd like
Move the main part of udf-examples to spark-rapids-examples.
udf-examples depends on the release dist jar in Central Maven (Note the snapshot jar is not published to Central Maven).
Keep some simple cases in the original udf-examples.
Update the rapids code if necessary, such as:
The udf-examples should only depend on dist, but it transitively depends on the sql-plugin module, and sql-plugin jar is not published to Central Maven, so should find the a way to build a clean dist jar that depends on no other jars.

Describe alternatives you've considered

Additional context
See #3934

[jlowe]

This is essentially a duplicate of #3971

[res-life]

Close this and keep #3971