Map object position as tile coordinates, map objects correctly snap to each tile now when moving, and fixed bug of placing objects over eachother on the same tile

src/components/screens/MapEditor.vue

@@ -4,7 +4,7 @@
       <Scene name="main" @preload="preloadScene">
         <div v-if="!isLoaded" class="absolute top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 text-white text-3xl font-ui">Loading...</div>
         <div v-else>
-          <Map :key="mapEditor.currentMap.value?.id" />
+          <Map v-if="mapEditor.currentMap.value" :key="mapEditor.currentMap.value?.id" />
           <Toolbar
             ref="toolbar"
             @save="save"