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/DMView.swift

@@ -0,0 +1,39 @@
+//
+//  DMView.swift
+//  damus
+//
+//  Created by William Casarin on 2022-07-01.
+//
+
+import SwiftUI
+
+struct DMView: View {
+    let event: NostrEvent
+    let damus_state: DamusState
+    
+    var is_ours: Bool {
+        event.pubkey == damus_state.pubkey
+    }
+    
+    var body: some View {
+        HStack {
+            if is_ours {
+                Spacer()
+            }
+            
+            NoteContentView(privkey: damus_state.keypair.privkey, event: event, profiles: damus_state.profiles, content: event.get_content(damus_state.keypair.privkey))
+                .foregroundColor(is_ours ? Color.white : Color.primary)
+                .padding(10)
+                .background(is_ours ? Color.accentColor : Color.secondary.opacity(0.15))
+                .cornerRadius(8.0)
+                .tint(is_ours ? Color.white : Color.accentColor)
+        }
+    }
+}
+
+struct DMView_Previews: PreviewProvider {
+    static var previews: some View {
+        let ev = NostrEvent(content: "Hey there *buddy*, want to grab some drinks later? 🍻", pubkey: "pubkey", kind: 1, tags: [])
+        DMView(event: ev, damus_state: test_damus_state())
+    }
+}