More cleanup of operations and post-paste behavior

* Support move, rotate, reflect, delete post paste on multiselection
* Improve text and error msgs for singular vs multi selections
* Move `disabled` checks from actions to operations
* Reproject center of rotation (closes #3667)
* Cleanup tests

modules/actions/delete_node.js

@@ -31,10 +31,5 @@ export function actionDeleteNode(nodeId) {
     };
 
 
-    action.disabled = function() {
-        return false;
-    };
-
-
     return action;
 }