Easier way to reverse the order of the keys

[misaki-eymard]

Currently, if you want to reverse the order of the keys in an animation, you can do so using box selection and scale as described in the Spine User Guide: https://esotericsoftware.com/spine-dopesheet#Box-selection
However this becomes somewhat complicated when the keys are in fractional frames, as noted in comment #811. It may also be necessary to display all bones and be careful not to miss any key selections, which can be tedious in complex skeletons.
Reversing keys may be often done to create transition animations, so it would be useful to add a one-click button or something to do this.

Related forum post:
https://esotericsoftware.com/forum/d/26598-after-splicing-ab-animation-into-c-animation-some-actions-become-invalid/13