Move frame positions

[MrMe1024]

rearranging frames will become invaluable if a feature to import frames is added. It will also be useful for adding frames to replace bad ones.

[charlielee]

I'm surprised we didn't already have an open issue for this. Thank you for creating an issue.

[blackboxlogic]

Along with MOVE, please consider multi-select, so entire scenes can be re-arranged without much pain. Cool project, thanks for making it.