fix #42031: slur position relative to flipped articulation

I am assuming the reason we originally did not bother doing a layout after flipping articulations was that it wasn't needed - slurs didn't originally adjust to them.  But now that slurs do adjust to articulations, we need to layout after flipping articulation.  Plus the fix I made to not base slur to aritculation if it is on the stem side.  It's already the case that we don't base to articulations for slurs that are not on the note side, but if the slur was on note side but articulation was on stem side, we were getting a conflict.