New Example for Sedona Java Implementation

On a project, I had occasion to test Sedona geoparquet capabilities to potentially replace a PostGIS database with over 100M rows. With an existing Spring Boot API application, I had been hoping to find some manner of read-made Java implementation for Sedona that could be referenced without creating a Scala build, and which could be used to interpret the data stored as geoparquet.

One thing I've found are many examples of this same approach being accomplished with Python, and while attractive I wanted to reuse my API infrastructure. I mocked up test case with a local Spark cluster and found that it worked pretty well.

I was wondering if there was any interest in seeing this small-scope example in the public Sedona repo? [ I have a complete and fairly polished version on my fork here](https://github.com/aleczoeller/sedona/tree/java-sql-example/examples), under the java-spark-sql folder/template, complete with JUnit tests (`mvn test`) and a small sample geoparquet file. I also made a small update to the readme in this examples directory.

Review the proposed implementation in the linked fork under examples/java-sql-example, including its README and sample geoparquet file. Run `mvn test` in the example to verify the existing JUnit tests, then compare the example with the repository's current example structure. Done means the Java Spark SQL example and its documentation are suitable for inclusion in the public repository.

Written by the indexing model from the issue text.