Adjusting animation speeds in Sprite Editor

[MACK-GB]

Is your feature request related to a problem? Please describe.
There are many times that a dev might duplicate frames of a sprite animation while leaving some as single so as to create unique frame rates. It would be helpful to see the animation play at the intended speed while working in the Sprite Editor.

Describe the solution you'd like
Have the ability to change the animation playback speeds in the Sprite Editor - same as the options available to the dev in the Game World's options/events.

Describe alternatives you've considered
As far as I can tell, other than just playing it back at the wrong speed and envisioning it, the next best option is to set the animation up on an actor in the Game World and run the build.

Additional context
No additional context

[joeledge]

This would be really handy and save rebuilding the project multiple times to see if an animation works best at speed 5, 6 or 7.