Assign SE-0434 to the global actors usability proposal and put it in review

Author: rjmccall

proposals/NNNN-global-actor-isolated-types-usability.md renamed to proposals/0434-global-actor-isolated-types-usability.md

@@ -1,9 +1,9 @@
 ## Usability of global-actor-isolated types
 
-* Proposal: [SE-NNNN](NNNN-global-actor-isolated-types-usability.md)
+* Proposal: [SE-0434](0434-global-actor-isolated-types-usability.md)
 * Authors: [Sima Nerush](https://github.com/simanerush), [Matt Massicotte](https://github.com/mattmassicotte), [Holly Borla](https://github.com/hborla)
-* Review Manager: TBD
-* Status: **Awaiting implementation**
+* Review Manager: [John McCall](https://github.com/rjmccall)
+* Status: **Active review (April 10th...22nd, 2024)**
 * Implementation: On `main` gated behind `-enable-experimental-feature GlobalActorIsolatedTypesUsability`
 * Review: ([pitch](https://forums.swift.org/t/pitch-usability-of-global-actor-isolated-types/70799))