Switch to core-js for polyfills

package.json

@@ -50,9 +50,8 @@
     "abortcontroller-polyfill": "^1.4.0",
     "aes-js": "^3.1.2",
     "alif-toolkit": "^1.2.9",
-    "browser-polyfills": "~1.5.0",
+    "core-js": "^3.6.5",
     "diacritics": "1.3.0",
-    "es6-symbol": "^3.1.3",
     "fast-deep-equal": "~3.1.1",
     "fast-json-stable-stringify": "2.1.0",
     "lodash-es": "~4.17.15",
@@ -63,7 +62,7 @@
     "pannellum": "2.5.6",
     "rbush": "3.0.1",
     "regenerator-runtime": "^0.13.7",
-    "string.fromcodepoint": "1.0.0",
+    "whatwg-fetch": "^3.4.1",
     "which-polygon": "2.2.0"
   },
   "devDependencies": {