WBS is incorrect when applying cut-paste changes

[bmblb]

Steps to reproduce:

1. Create two Gantt charts using same data, store should contain parent with 2+ children and a sibling. Also, store should be sorted by WBS.
2. Select all siblings, cut them and paste to sibling.
3. Take project changes and apply them to 2nd Gantt chart.

When you apply changes to the 2nd Gantt chart, you'll notice WBS is different for changed records:

1 Task 1
// cut/paste these
1.1 Task 11
1.2 Task 12
2 Task 2
3 Task 3

// source Gantt
1 Task 1
2 Task 2
3 Task 11
4 Task 12
5 Task 3

// target Gantt
1 Task 1
2 Task 11
3 Task 12
4 Task 2
5 Task 3

[bmblb]

This problem is caused by a solution to #7135 which is trying to figure if remote operation is an outdent. There is not enough information to reliably tell outdent apart from reorder/cut/paste.
Reported issue with wrong WBS is resolved, but visible tree will differ between projects.