refactor: extract application construction and lifecycle

package.json

@@ -64,6 +64,8 @@
   "exports": {
     "./infrastructure": "./src/data/infrastructure.js",
     "./infrastructure/geojson": "./src/data/localGeojsonCore.js",
-    "./infrastructure/lod": "./src/data/localGeojsonLod.js"
+    "./infrastructure/lod": "./src/data/localGeojsonLod.js",
+    "./application": "./src/app/application.js",
+    "./application/viewer": "./src/app/viewer.js"
   }
 }