NPCs should be kinematic bodies

[michalpelka]

NPCs should be kinematics bodies. Currently NPC is a robot with collider and actor attached.
That has multiple drawbacks:

• heavy to simulate for large number of NPCs
• needs groups and layer to prevent from collision (hack like Added human worker to collision group that should collide only with Ground layer #19)
• affected by gravity
• uses ROS 2 gem dependency to affect

I proposed to use kinematic body + raycasting in opposite direction to gravity. In contrast to current implementation:

• It can use AZFramework::Physics API (instead of ROS 2)
• We can remove dependency on ROS 2 gem
• It won't need to have collision layers and groups, since we can disable kinematic body collision
• It will work fine in non-planar scenarios (due to kinematic nature)
• Will be more predictable.
• Prefabs will be much simpler, without need for overrides
• No noise from NPCs in ROS 2 topics.