Allow interpolation of scales

[janhohenheim]

Objective

For avian_interpolation, I want to have a clean separation between gameplay transforms and render transforms. Avian's best version of a gameplay scale is currently Collider::scale. However, this is not ergonomically interpolatable due to two reasons:

• Collider::scale is not initialized with the right scale, meaning that my observers that listen for its insertion will read wrong initial data, and
• It is automatically synced to the GlobalTransform, making it hard to change the Transform according to the Collider::scale without affecting it back in turn

Related to #444

Solution

• Set the Collider::scale correctly in its on_add hook
• Allow an opt-out via SyncConfig

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Changelog

• You can now opt-out of Transform to Collider::scale syncing by using the new SyncConfig::transform_to_collider_scale field.

[janhohenheim]

@Jondolf could you help me out with the CI failure? With the .into it says that it is not needed for some features, but without it, we get this:

ofc I could just ignore the clippy lint, but I'd like to know how the rest of the Avian codebase does this. This is not a case of .adjust_precision, is it?

[Jondolf]

This is not a case of .adjust_precision, is it?

It most likely is; set_scale currently takes a Vector, so you need to convert the transform's Vec2/Vec3 scale to it using .adjust_precision.

[janhohenheim]

Yep, you were right :D

[Jondolf]

Looks good, thanks!