fixup! feat(binding_mqtt): support MQTT URI scheme

lib/src/binding_mqtt/mqtt_extensions.dart

@@ -62,6 +62,16 @@ extension MqttUriExtension on Uri {
 
     throw StateError('MQTT URI scheme $scheme is not supported.');
   }
+
+  String get _mqttTopic {
+    final path = Uri.decodeComponent(this.path);
+
+    if (path.isEmpty) {
+      return path;
+    }
+
+    return path.substring(1);
+  }
 }
 
 /// Additional methods for making MQTT [Form]s easier to work with.
@@ -99,28 +109,21 @@ extension MqttFormExtension on Form {
       return topic;
     }
 
-    final path = Uri.decodeComponent(href.path);
-
-    if (path.isEmpty) {
-      return path;
-    }
-
-    return path.substring(1);
+    return href._mqttTopic;
   }
 
   /// Gets the MQTT topic for subscribing from this [Form].
   ///
   /// If present, this getter uses the dedicated vocabulary term `filter`.
-  /// Otherwise, the URI query from the `href` field is being used as a
-  /// fallback.
+  /// Otherwise, the URI path from the `href` field is being used as a fallback.
   String get topicFilter {
     final topic = _obtainVocabularyTerm<String>('filter');
 
     if (topic != null) {
       return topic;
     }
 
-    return Uri.decodeComponent(href.query.replaceAll('&', '/'));
+    return href._mqttTopic;
   }
 
   /// Gets the MQTT `retain` value from this [Form] if present.