Blender Git Loki

Fix T58928: New Action causes crash when duplicating bone

Basically, armature update is not supposed to be run in edit mode.
This worked in master and new dependency graph because nobody was
tagging armature for an update.

But with all those copy-on-write and other things we can't ensure
tag doesn't happen (and we shouldn't). So now we ensure unwanted
code is not run from the code itself.

P.S. Deeper reason of this goes to the optimization of not updating
pose channels when in edit mode. Since pose doesn't define anything
there we don't want to be bothered with a pose update after every
operation which changes it.