[SPARK-7018][BUILD] Refactor dev/run-tests-jenkins into Python

This commit refactors the `run-tests-jenkins` script into Python. This refactoring was done by brennonyork in #7401; this PR contains a few minor edits from joshrosen in order to bring it up to date with other recent changes.

From the original PR description (by brennonyork):

Currently a few things are left out that, could and I think should, be smaller JIRA's after this.

1. There are still a few areas where we use environment variables where we don't need to (like `CURRENT_BLOCK`). I might get around to fixing this one in lieu of everything else, but wanted to point that out.
2. The PR tests are still written in bash. I opted to not change those and just rewrite the runner into Python. This is a great follow-on JIRA IMO.
3. All of the linting scripts are still in bash as well and would likely do to just add those in as follow-on JIRA's as well.

Closes #7401.

Author: Brennon York <brennon.york@capitalone.com>

Closes #9161 from JoshRosen/run-tests-jenkins-refactoring.