Implement NIP04: Encrypted Direct Messages

Closes #5

This adds encrypted direct message support to damus

Changelog-Added: Implement NIP04: Encrypted Direct Messages
Signed-off-by: William Casarin <jb55@jb55.com>

damus/Models/DirectMessagesModel.swift

@@ -0,0 +1,15 @@
+//
+//  DirectMessagesModel.swift
+//  damus
+//
+//  Created by William Casarin on 2022-06-29.
+//
+
+import Foundation
+
+class DirectMessagesModel: ObservableObject {
+    @Published var events: [(String, [NostrEvent])] = []
+    @Published var loading: Bool = false
+    
+    
+}