XWIKI-21558: If a macro is modified by another user while the macro edit modal...

XWIKI-21558: If a macro is modified by another user while the macro edit modal is open, we cannot update the macro
* Improve the way macros are updated after a remote patch is applied
* Save and entry in the Undo/Redo history after adding a macro (in order to trigger a change event).
* Add a test.