notify: add typesafe notifications

damus/Notify/NewMutesNotify.swift

@@ -0,0 +1,25 @@
+//
+//  NewMutesNotify.swift
+//  damus
+//
+//  Created by William Casarin on 2023-07-30.
+//
+
+import Foundation
+
+struct NewMutesNotify: Notify {
+    typealias Payload = Set<Pubkey>
+    var payload: Payload
+}
+
+extension NotifyHandler {
+    static var new_mutes: NotifyHandler<NewMutesNotify> {
+        .init()
+    }
+}
+
+extension Notifications {
+    static func new_mutes(_ pubkeys: Set<Pubkey>) -> Notifications<NewMutesNotify> {
+        .init(.init(payload: pubkeys))
+    }
+}