Rename ArmadaSparkSubmit to SparkSubmit and rearrange classpath so it gets called instead of the real SparkSubmit

Right now we have our own version of ./core/src/main/scala/org/apache/spark/deploy/SparkSubmit.scala

called ArmadaSparkSubmit

But that causes most tools to use the real SparkSubmit instead of ours.

Experiment with renaming ArmadaSparkSubmit back to SparkSubmit, and see if you can figure out a way to set the classpath so that ours always gets used intead of the real one.