Performance improvements, torch.compile() and benchmark

[Phil26AT]

• benchmark script for LightGlue on example images
• prefer torch sdp over official flash_attn
• add heuristics to disable pruning overhead on pairs with few keypoints
• plenty of performance improvements
• add support for torch.compile (jit) with static shapes (but supports adaptive-depth!). auto-pad to static shapes if in compile mode. This yields very large performance improvements with few keypoints

RTX 3080:

Intel i7 10700K: