Make landmark alignment case insensitive

[avolu]

When trying to register optode positions from a recent photogrammetric scan to the atlas it failed because not sufficient shared landmarks were found - simply because of different cases (Lpa vs LPA). This could easily happen again so i think we should make this case insensitive - likely here:

cedalion/src/cedalion/imagereco/forward_model.py

Line 483 in e357467

def align_and_snap_to_scalp(

[orabe]

This issue has been resolved in PR #132.

Solution: Added normalize_landmarks_labels() function to handle case-insensitive landmark name normalization. Maps common alternative names (e.g., "nasion", "left ear", "lpa") to canonical labels (Nz, LPA, etc.).

Usage: Call normalize_landmarks_labels(geo3d) before registration:

from cedalion.geometry.landmarks import normalize_landmarks_labels

geo3d = normalize_landmarks_labels(geo3d)
geo3d_snapped = head_ijk.align_and_snap_to_scalp(geo3d)