Drag-and-drop improvements for projects and issue pins (#29875)

1. Add "grabbing" cursor while dragging items:

![](c60845ff-7544-4215-aeaa-408e8c4ef03a)

2. Make project board only drag via their header, not via their whole
body.

![](62c27f3d-993a-481d-9cc3-b6226b4c5d61)

3. Fix some cursor problems in projects
4. Move shared options into `createSortable`.

(cherry picked from commit 7fda109aba6cd077343edef086b2f2ff60124f78)

web_src/js/features/repo-projects.js

@@ -58,8 +58,7 @@ async function initRepoProjectSortable() {
   createSortable(mainBoard, {
     group: 'project-column',
     draggable: '.project-column',
-    animation: 150,
-    ghostClass: 'card-ghost',
+    handle: '.project-column-header',
     delayOnTouchOnly: true,
     delay: 500,
     onSort: async () => {
@@ -86,8 +85,6 @@ async function initRepoProjectSortable() {
     const boardCardList = boardColumn.getElementsByClassName('cards')[0];
     createSortable(boardCardList, {
       group: 'shared',
-      animation: 150,
-      ghostClass: 'card-ghost',
       onAdd: moveIssue,
       onUpdate: moveIssue,
       delayOnTouchOnly: true,