Support new timestamp rule

> 613.7n. If a continuous effect generated by a static ability of an object and a continuous effect generated by a resolving spell or ability that applies to that object would receive a timestamp simultaneously, such as due to an effect that puts that object onto the battlefield and sets its characteristics (see rule 611.2e), the continuous effect from the object's own static ability receives an earlier relative timestamp.

Research questions:
1. after all the work it seems my part for ordering the effect from #6819 might no longer be needed - or is there still a case where it matters?
2. Luckily we also got some reasoning for it:
> Xu-Ifit is happier when the returned creatures can't grant themselves abilities after she went to all the trouble to take those abilities away.

- but while it matters for multiple layers currently in Forge above rule seems irrelevant in the ability layer because that removal static should just cause others to depend on it.
However if _Xu-Ifit_ returns something like _Possessed Aven_ - which starts to apply in earlier layer - it could be argued that the rule which makes it "continue to be applied" (even if removed) also means that a dependency due to (non)-"existence of the first effect" isn't happening? 🤔