Allow not overwriting entity visibility with debug renderer

[Dentosal]

Objective

Currently PhysicsDebugPlugin always overwrites Visibility component of the entity with Collider. This is sometimes undesirable, as I want to have entities whose visibilty is part of the game logic.

Solution

This PR allows the debug renderer to instead not overwrite the visibilty when configured to do so. The PR also changes the default value to not overwrite, as it always forced colliders to be visibile before.

Alternatives

An Option<Visibility> could be used instead of an enum, but I hope this version is more readable. We could also just not change visibility if hide_meshes is set to false, but this would unexpectedly affect visibility if this is toggled.

---

Changelog

This section is optional. If this was a trivial fix, or has no externally-visible impact, you can delete this section.

• What changed as a result of this PR?
• If applicable, organize changes under "Added", "Changed", or "Fixed" sub-headings
• Stick to one or two sentences. If more detail is needed for a particular change, consider adding it to the "Solution" section
  • If you can't summarize the work, your change may be unreasonably large / unrelated. Consider splitting your PR to make it easier to review and merge!

Migration Guide

The hide_meshes: bool field of PhysicsGizmos (global) and DebugRender (entity) has been replaced with mesh_visibility: MeshVisibility. The old value false should be MeshVisibility::Overwrite(Visibility::Visible), and true should be MeshVisibility::Overwrite(Visibility::Hidden).

The debug renderer no longer forces entities with Collider to be visible by default To restore old behavior, we have to set the mesh_visibility field to one of the variants described above.