Add yololite coreML

[leeclemnet]

What does this PR do?

Adds yololite to the supported model families in roboflow-swift.

Works from coreml models exported from roboflow-train: https://github.com/roboflow/roboflow-train/pull/750

Minor refactor to pull math-only NMS utilities out of availability gate.

Type of Change

• New feature (non-breaking change that adds functionality)

Testing

• I have tested this change locally
• I have added/updated tests for this change

Test details:

Added object detection unit test based on hard hat detection model here: https://app.roboflow.com/lee-sandbox/hard-hat-workers-ry4vt/4

One-off local test script using the new RFYoloLiteObjectDetectionModel

• yololite-edge-n on chess-pieces

• yololite-edge-m on chess-pieces

• yololite-edge-m on hard-hat-workers

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code where necessary, particularly in hard-to-understand areas
• My changes generate no new warnings or errors
• I have updated the documentation accordingly (if applicable)

Additional Context