`ColliderDebugColor` should contain a `Color`

`ColliderDebugColor` now contains an `Hsla`, which means the user's colors now need to undergo conversion from

(User's color space if not `Hsla`) ->
`Hsla`->
`Color` (no color space conversion here) ->
(deep in Bevy's gizmo renderer, `LinearRgba`)

`bevy_rapier` also seems to convert from `Hsla` to `[f32, 4]` and back to `Hsla` for no discernible reason in `object_color` and e.g. `draw_line`.

Given that the ultimate destination of these colors is `Gizmos`, and `Gizmos` want `Color`, I think we should just use `Color`.

Start by tracing ColliderDebugColor and the object_color and draw_line paths mentioned in the issue, then compare them with the Gizmos color API. Check where Hsla and array conversions occur. Done means the debug-color path uses Color consistently and the redundant conversions are removed without changing rendered colors.

Written by the indexing model from the issue text.