Folks didn't seem to like the "only clear when there are collisions" behaviour. Paste Special remains available to "force keep". Fixes https://gitlab.com/kicad/code/kicad/issues/4933 Fixes https://gitlab.com/kicad/code/kicad/issues/4744
Also changes the normal paste behaviour to only clear annotations when a collision is found. Fixes: lp:1837002 * https://bugs.launchpad.net/kicad/+bug/1837002