Enhance git pull/push over HTTPs tests

The issue is to update git pull over HTTPs test to use similar approach as git_push test - allow user to specify the specific commit SHAs that they want to pull. This will enable to customise git pull size if needed.

Additionally it will be helpful to explore changing git_*_data to array and provide users the ability to pull/push multiple commits simultaneously to address possible cache issues when running tests for extensive period of time.