Added collisions with objects on scene

Player will now be stopped by fences
Also added the possibility to define the size of ground
Also edited speed of animations
Also optimized the loading of fences

src/utils/animateMesh.js

@@ -1,6 +1,6 @@
 import * as THREE from 'three';
 
-const ANIMATION_SPEED_MULTIPLIER = 1.4;
+const ANIMATION_SPEED_MULTIPLIER = 1.6;
 let mixersToUpdateEachFrame = [];
 
 export function addAnimationMixerOnMesh(mesh, actions){