Add e2ee settings

lib/utils/beautify_string_extension.dart

@@ -0,0 +1,15 @@
+extension BeautifyStringExtension on String {
+  String get beautified {
+    String beautifiedStr = "";
+    for (int i = 0; i < this.length; i++) {
+      beautifiedStr += this.substring(i, i + 1);
+      if (i % 4 == 3) {
+        beautifiedStr += "    ";
+      }
+      if (i % 16 == 15) {
+        beautifiedStr += "\n";
+      }
+    }
+    return beautifiedStr;
+  }
+}

lib/utils/event_extension.dart

@@ -162,7 +162,9 @@ extension LocalizedBody on Event {
         break;
       case EventTypes.Encryption:
         localizedBody =
-            I18n.of(context).activatedEndToEndEncryption(senderName);
+            I18n.of(context).activatedEndToEndEncryption(senderName) +
+                ". " +
+                I18n.of(context).needPantalaimonWarning;
         break;
       case EventTypes.Encrypted:
         localizedBody = I18n.of(context).couldNotDecryptMessage;

lib/utils/famedlysdk_store.dart

@@ -36,6 +36,24 @@ class Store extends StoreAPI {
     return await secureStorage.write(key: key, value: value);
   }
 
+  Future<Map<String, DeviceKeysList>> getUserDeviceKeys() async {
+    final deviceKeysListString = await getItem(_UserDeviceKeysKey);
+    if (deviceKeysListString == null) return {};
+    Map<String, dynamic> rawUserDeviceKeys = json.decode(deviceKeysListString);
+    Map<String, DeviceKeysList> userDeviceKeys = {};
+    for (final entry in rawUserDeviceKeys.entries) {
+      userDeviceKeys[entry.key] = DeviceKeysList.fromJson(entry.value);
+    }
+    return userDeviceKeys;
+  }
+
+  Future<void> storeUserDeviceKeys(
+      Map<String, DeviceKeysList> userDeviceKeys) async {
+    await setItem(_UserDeviceKeysKey, json.encode(userDeviceKeys));
+  }
+
+  String get _UserDeviceKeysKey => "${client.clientName}.user_device_keys";
+
   _init() async {
     final credentialsStr = await getItem(client.clientName);