Add better object updates

backend/src/physics/physicals/dynamic-physical.ts

@@ -1,6 +1,9 @@
+import { UpdateObjectMessage } from 'shared/lib/src/objects/update-object-message';
 import { PhysicalBase } from './physical-base';
 
 export interface DynamicPhysical extends PhysicalBase {
   readonly canMove: true;
   step(deltaTimeInMilliseconds: number): void;
+
+  calculateUpdates(): UpdateObjectMessage | null;
 }