Add DM button to profile

Signed-off-by: William Casarin <jb55@jb55.com>

damus/Models/DirectMessagesModel.swift

@@ -8,8 +8,26 @@
 import Foundation
 
 class DirectMessagesModel: ObservableObject {
-    @Published var events: [(String, [NostrEvent])] = []
+    @Published var dms: [(String, DirectMessageModel)] = []
     @Published var loading: Bool = false
     
+    func lookup_or_create(_ pubkey: String) -> DirectMessageModel {
+        if let dm = lookup(pubkey) {
+            return dm
+        }
+        
+        let new = DirectMessageModel()
+        dms.append((pubkey, new))
+        return new
+    }
     
+    func lookup(_ pubkey: String) -> DirectMessageModel? {
+        for dm in dms {
+            if pubkey == dm.0 {
+                return dm.1
+            }
+        }
+        
+        return nil
+    }
 }