Fix undo redo tests part 1

[mstrofbass]

This fixes one of the two skipped undo/redo tests by awaiting the initialize call and removing the use of the fake timers.

Key insight here is that since the tests that use initialize were originally skipped, the code has changed in such a way that we can await the initialize call without problem.

The second test is slightly more difficult to fix so wanting to get this merged instead of waiting.

Solves part of #2145