Fix extension bindings for motion collision/result structs

[mihe]

It seems some changes were made to PhysicsServer3D::MotionCollision (#63650) and PhysicsServer3D::MotionResult (#64195) without updating the extension bindings defined in register_server_types(), causing a mismatch in struct layout between the engine and (for example) godot-cpp. This means that when writing to certain fields of these structs from an extension, such as when implementing PhysicsServer3DExtension::_body_test_motion, you end up stomping on memory of other fields.

This PR updates the bindings to again be in sync with the respective structs.