[Feature Request] Add override fields for effect properties to aura Rule Element

[pinkflumph]

Request:
Add fields to aura Rule Element that would override effect properties, or make duration override optional.

Issue this is designed to resolve:
The aura Rule Element currently automatically overrides the duration of the effect it applies to be unlimited, which limits its applicability.

In particular, this severely restricts the usefulness of unchecking the "remove on exit" checkbox, since all effects applied by an aura are automatically made permanent.

Use case:
Applying effects that persist outside of an aura but retain their limited duration simplifies the implementation of instantaneous AoE spells that apply effects in an emanation, such as Courageous Anthem, by briefly applying the aura to a token, leveraging applyAreaEffects (see example code attached as txt)

courageous_anthem_macro_v3.txt