More MessageBus-related silliness to resolve issue with toggling visibility/mute/locking
status of F-Curves/Groups/etc., as well as other things like modifying active keyframe's
values, or changing properties of F-Modifiers.
I've now ended up just whitelisting in the region subscribers all the animation-related
structs in RNA. But still, that may not be enough to deal with potential issues later
with the property sliders (shown per channel, optionally), which can come from anywhere.
(Spring bug)
ce5fa2deca