Fix: handle RetinaFace landmarks correctly (nose, mouth_left and mouth_right)

[AdaiasMagdiel]

This PR fixes #23.

• Issue: Unknown named parameter $nose when using Detector::RETINAFACE
• Cause: RetinaFace returns landmarks (nose, mouth_left, mouth_right, etc.) not properly mapped.
• Fix: Normalize landmark keys before constructing the object.

Tested with:

• Detector::RETINAFACE
• FaceRecognitionModel::ARCFACE

Result: represent() now returns embeddings successfully without crashing.