Enable 0044-mime-type tests for ACA-Py

[nodlesh]

At this point there are no Mime Type tests running in the ACA-Py runsets.

• Add mime-type argument handling in the start api for restarting the agent.
• Add mime-type tests to the runset tag configuration

[swcurran]

@nodlesh — please add the command to run these specific tests so it will be easier to run them and see the logs.

Thanks