fix/feature [#35085] Loop cut slide

Loop cut slide now works with multicut.

issue is that since edge slide now supports more configurations, cases where loop-cut-slide silently failed before,
now slide (albeit in an awkward way at times).

Fix this my adjusting the selection of after loopcut so edge slide can properly operate on it.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56318 954f8c5b-7b00-dc11-b283-0030488c597c