Set ECS IK target positions from mocap data via rig world positions

[AidanCaruso]

Summary

🤖 Generated by Copilot at 283478f

Refactor applyInputSourcePoseToIKTargets function to take IK target entities as parameters and add support for motion capture rigs. Update AvatarAnimationSystem to use the refactored function and only call it for the local avatar.

References

closes #insert number here

Explanation

🤖 Generated by Copilot at 283478f

• Refactor applyInputSourcePoseToIKTargets function to take IK target entities as parameters instead of generating them from input source UUIDs (link, link, link)
• Add support for motion capture rig component to applyInputSourcePoseToIKTargets function, using getWorldPosition method to set IK target positions (link, link)
• Remove unused imports of EntityUUID and UUIDComponent from packages/engine/src/avatar/functions/applyInputSourcePoseToIKTargets.ts (link, link)

🤖 Generated by Copilot at 283478f

AvatarAnimationSystem controls our fate
We are the puppets of the execute state
But we can break free from the UUID chains
With applyInputSourcePoseToIKTargets we can use our own motion capture brains

QA Steps

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Checklist

• If this PR is still a WIP, convert to a draft
• When this PR is ready, mark it as "Ready for review"
• ensure all checks pass
• Changes have been manually QA'd
• Changes reviewed by at least 2 approved reviewers