Implement batched Undo

[adamdbrw]

For each operation understood as single AI model response.

[jhanca-robotecai]

Undo/redo should be handled by O3DE Editor (it is handled correctly now) and by the feature, which is a black box from the framework's perspective.

This issue is not related to the GenAIFramework, but I will keep it open until we port the basic scene generation system and verify it is okay there.