Add ECS collisions

[Nitero]

When making a project with ECS there are colliders on entitites which are different to normal colliders. Unfortunately it doesnt look like Cinemachine supports interactions with these out of the box. This would be great especially for the CinemachineCollider extension

Since it doesnt look like you can easily override CinemachineCollider I tried to add a custom CinemachineColliderEcs extension instead, but to get it to work I had to copy over the RuntimeUtility into the project since the methods DestroyScratchCollider and GetScratchCollider are internal... Surprisingly having both the normal CinemachineCollider and my custom CinemachineColliderEcs on the same virtual camera seems to work pretty well, but I think it would be ideal to merge these two so the settings are unified (apart from the tags, which are different for the two physics systems).

I guess I could just try to combine both of them in the same script, but that doesnt feel trivial (dont think my implementation is perfect) and there also seems to be some other functionality that depends on collisions like the Cinemachine3rdPersonFollow extension, so maybe the ECS support needs to be integrated more deeply starting with the RuntimeUtility and use wrappers for the RaycastHit etc to hide the fields for normal/ECS such as Collider/Aabb?

CinemachineColliderEcs.txt

[glabute]

Thank you for this. We do plan to add Unity Physics support to Cinemachine. We still need to think about what exactly it would look like, but your attempt is a good first stab at it.