Support applying a flipped pose, useful when animating symmetrical rigs.
This is similar transforming a pose with symmetry enabled, it need not be used as part of transforming.
Optionally use the 3D cursor as an origin to flip root poses
that aren't located near the objects origin which would otherwise
flip them along the objects local X axis.
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**Motivation**
This patch adds functionality to flip an entire pose on the X axis using a symmetrical rig.
Currently the only way to do this is to copy the pose, then use paste-flipped, while this can work, it doesn't give much control and isn't as convenient to integrate into other tools.
tested with spring.blend {F9899281}
**Alternative Solutions**
An alternative approach could be to flip input values directly, see: D10781.
**Limitations**
This only flips transform channels, it's possible custom properties are used to control values which are not flipped.
**Open Topics**
- Other pose channel settings could be handled (curved bone roll, ease ... etc).