Extract the Update type from any supported schema type.
The Update type represents what a node can return to update the state. All fields are optional since nodes only need to return the fields they modify.
Supports:
ExtractUpdateType: Schema extends AnnotationRoot<
SD
> UpdateType<SD> : UpdateType<ToStateDefinition<Schema>> extends U [U] extends [never] Partial<FallbackBase> : U : Partial<FallbackBase>