added git repository version option

[fkgruber]

What issue does this pull request solve?

Currently we can't select a specific github branch when submitting a job

What is the solution?

add mainRepoGitRef argument so we can add the branch that we want to use.

Testing

Briefly describe how the change was tested. The purpose of this section is that a reviewer can identify a test gap, if any.

I tested on my company's setup

• Unit test(s)

Pull Request Reminders

• Has the changelog been updated
• Has relevant documentation been updated?
• Does the code follow [Python Style Guide] (https://black.readthedocs.io/en/stable/the_black_code_style/current_style.html)
• Are the existing unit tests still passing?
• Have new unit tests been added to cover any changes to the code?
• Has the JIRA ticket(s) been linked above?

References (optional)