Add creation datetime to output

[jburnhams]

Useful with lots of clips where you want to preserve the input timestamp on the output for sorting etc

Contributor Checklist

• Review Contribution Guidelines
• Agree to the terms of Developer Certificate of Origin.
• Make sure all contributed code can be distributed under the terms of the GNU Licence
• Check "Allow edit from maintainers" option in pull request so that additional changes can be pushed by maintainers if required.
• Unit tests created/updated (under tests) to verify logic, and approval tests for UI Widgets
• Update Examples - Under build-scripts/examples, and regenerate examples docs if required ( make doc-examples )
• Ensure that tests pass locally - this can be tricky for approval tests with maps or text though.
• Check that pre-release tests work ( make test-distribution )

[time4tea]

Sorry not ignoring you. Been busy with lots of things. Will check soon. Thank you!