MarkerOperation is incorrectly transformed by SplitOperation in scenario when start and split is at the same position #18449
Description
📝 Provide detailed reproduction steps (if any)
- Create a marker which starts at the end of a paragraph, e.g.
<p>[</p><p>Foo]</p>. - Merge elements.
- Undo.
✔️ Expected result
The marker is correctly restored.
❌ Actual result
The marker has incorrect start position: <p></p><p>[Foo]</p>.
📃 Other details
You can test this using e.g. track changes and insertion suggestion.