## Summary
Backport of #7447 to core/1.34.
Fixes issue when dragging a group that had inner groups when in vue
mode.
When dragging the outer group in Vue mode:
1. getAllNestedItems(selected) returns ALL items: outer group + inner
groups + nodes
2. moveChildNodesInGroupVueMode loops through all items
3. For outer group G1: calls G1.move(delta, true) then
moveGroupChildren(G1, ...)
4. moveGroupChildren calls G2.move(delta) (no skipChildren) - this moves
G2 AND G2's children!
5. Then the loop reaches G2: calls G2.move(delta, true) - moves G2 again
6. Plus moveGroupChildren(G2, ...) processes G2's children again
This PR fixes it by adding `skipChildren=true` to the `move` call.
0c56b7b178