CWA-164 | added biometric authentication

lib/src/domain/common/biometric_auth.dart

@@ -0,0 +1,24 @@
+import 'package:local_auth/local_auth.dart';
+import 'package:flutter/services.dart';
+import 'package:cake_wallet/generated/i18n.dart';
+
+class BiometricAuth {
+
+  Future<bool> isAuthenticated() async {
+    final LocalAuthentication _localAuth = LocalAuthentication();
+
+    try {
+      return await _localAuth.authenticateWithBiometrics(
+          localizedReason: S.current.biometric_auth_reason,
+          useErrorDialogs: true,
+          stickyAuth: false
+      );
+    } on PlatformException
+    catch(e) {
+      print(e);
+    }
+
+    return false;
+  }
+
+}