Add abortcontroller-polyfill to support abortable fetch calls

modules/id.js

@@ -1,3 +1,5 @@
 import 'browser-polyfills';
+import 'abortcontroller-polyfill/dist/polyfill-patch-fetch';
+
 import * as iD from './index';
 window.iD = iD;

package.json

@@ -37,6 +37,7 @@
     "@mapbox/togeojson": "0.16.0",
     "@mapbox/vector-tile": "^1.3.1",
     "@turf/bbox-clip": "^6.0.0",
+    "abortcontroller-polyfill": "~1.3.0",
     "alif-toolkit": "^1.2.5",
     "browser-polyfills": "~1.5.0",
     "diacritics": "1.3.0",