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/Views/DirectMessagesView.swift

@@ -0,0 +1,52 @@
+//
+//  DirectMessagesView.swift
+//  damus
+//
+//  Created by William Casarin on 2022-06-29.
+//
+
+import SwiftUI
+
+struct DirectMessagesView: View {
+    let damus_state: DamusState
+    @Binding var dms: [(String, [NostrEvent])]
+    
+    var MainContent: some View {
+        ScrollView {
+            VStack {
+                ForEach(dms, id: \.0) { tup in
+                    let evs = Binding<[NostrEvent]>.init(
+                        get: { tup.1 },
+                        set: { _ in }
+                    )
+                    let chat = DMChatView(damus_state: damus_state, pubkey: tup.0, events: evs)
+                    NavigationLink(destination: chat) {
+                        EventView(damus: damus_state, event: tup.1.last!, pubkey: tup.0)
+                    }
+                    .buttonStyle(PlainButtonStyle())
+                }
+            }
+        }
+    }
+    
+    var body: some View {
+        MainContent
+            .navigationTitle("Encrypted DMs")
+    }
+}
+
+struct DirectMessagesView_Previews: PreviewProvider {
+    static var previews: some View {
+        let ev = NostrEvent(content: "encrypted stuff",
+                               pubkey: "pubkey",
+                               kind: 4,
+                               tags: [])
+        let dms = Binding<[(String, [NostrEvent])]>.init(
+            get: {
+                return [ ("pubkey", [ ev ]) ]
+            },
+            set: { _ in }
+        )
+        DirectMessagesView(damus_state: test_damus_state(), dms: dms)
+    }
+}