"Blend from Shape" lists keys from active object and applies to all selected
objects that have keys with a matching name.
Changes from reviewer (Dalai Felinto):
* Code Style.
* Move Object **objects after sanity check to prevent leak when
returning OPERATOR_CANCELLED.
* Skip objects that have no selected vertex.
* Fixed existent comments code-style: Since we are changing the indentation of
these lines, may as well correct this as well.
Differential Revision: https://developer.blender.org/D3656
6ae09dfcad