Add an empty view when a tagged user isnt found

Changelog-Added: Show a custom view when tagged user isn't found

damus/Views/Empty Views/EmptyUserSearchView.swift

@@ -0,0 +1,37 @@
+//
+//  EmptyUserSearchView.swift
+//  damus
+//
+//  Created by eric on 4/3/23.
+//
+
+//
+//  EmptyUserSearchView.swift
+//  damus
+//
+//  Created by eric on 4/3/23.
+//
+
+import SwiftUI
+
+struct EmptyUserSearchView: View {
+    var body: some View {
+        VStack {
+            Image(systemName: "person.fill.questionmark")
+                .font(.system(size: 35))
+                .padding()
+            Text("Could not find the user you're looking for", comment: "Indicates that there are no users found.")
+                .multilineTextAlignment(.center)
+                .font(.callout.weight(.medium))
+        }
+        .foregroundColor(.gray)
+        .padding()
+    }
+}
+
+struct EmptyUserSearchView_Previews: PreviewProvider {
+    static var previews: some View {
+        EmptyUserSearchView()
+    }
+}
+

damus/Views/Posting/UserSearch.swift

@@ -74,11 +74,16 @@ struct UserSearch: View {
     var body: some View {
         ScrollView {
             LazyVStack {
-                ForEach(users) { user in
-                    UserView(damus_state: damus_state, pubkey: user.pubkey)
-                        .onTapGesture {
-                            on_user_tapped(user: user)
-                        }
+                Divider()
+                if users.count == 0 {
+                    EmptyUserSearchView()
+                } else {
+                    ForEach(users) { user in
+                        UserView(damus_state: damus_state, pubkey: user.pubkey)
+                            .onTapGesture {
+                                on_user_tapped(user: user)
+                            }
+                    }
                 }
             }
         }