[SPARK-13302][PYSPARK][TESTS] Move the temp file creation and cleanup outside of the doctests

Some of the new doctests in ml/clustering.py have a lot of setup code, move the setup code to the general test init to keep the doctest more example-style looking.
In part this is a follow up to https://github.com/apache/spark/pull/10999
Note that the same pattern is followed in regression & recommendation - might as well clean up all three at the same time.

Author: Holden Karau <holden@us.ibm.com>

Closes #11197 from holdenk/SPARK-13302-cleanup-doctests-in-ml-clustering.