Remove mock outputs and add quiet parameter

[eqrx]

This commit implements the quiet parameter of runner that was requested to be ported to the SDK. I looked through the code and found only output to stdout that was used for development. Removed it.

Quiet option in jobs can be used in the future to decide if informal output should be done at all.

[Shrews]

I'm not familiar with what was requested for this, but I sort of feel like these print() statements being removed should be replaced with some proper logging ability.

[eqrx]

@Shrews So far no decision has been made how we want to log AFIK. Now that you say it I totally agree that it would be a better approach to add some proper logging. But since I am out of the picture soon I would refrain from deciding on what would be best.