Match phys::System static group handlers

[RobbyV2]

I made the StaticGroupHandlerId parameter of both getters a SEAD_ENUM rather than an int, because the target spills that index to the stack and reloads it while indexing the outer dimension from w1 directly. The round trip comes from SEAD_ENUM's operator int() const volatile, and with an int both getters come out 40 bytes against the target's 52. The enumerator names are unknown, so they're written in the repo's _N placeholder style.

---

This change is