ui: Adds ember-auto-import and replaces the 3 places where we used npm: (#5952)

Also removes ember-browserify

ui-v2/app/utils/atob.js

@@ -1,4 +1,4 @@
-import base64js from 'npm:base64-js';
+import base64js from 'base64-js';
 export default function(str, encoding = 'utf-8') {
   // decode
   const bytes = base64js.toByteArray(str);

ui-v2/app/utils/btoa.js

@@ -1,4 +1,4 @@
-import base64js from 'npm:base64-js';
+import base64js from 'base64-js';
 export default function(str, encoding = 'utf-8') {
   // encode
   const bytes = new TextEncoder(encoding).encode(str);

ui-v2/package.json

@@ -57,7 +57,7 @@
     "clipboard": "^2.0.4",
     "dart-sass": "^1.14.1",
     "ember-ajax": "^3.0.0",
-    "ember-browserify": "^1.2.2",
+    "ember-auto-import": "^1.4.0",
     "ember-changeset-validations": "^2.1.0",
     "ember-cli": "~2.18.2",
     "ember-cli-app-version": "^3.0.0",

ui-v2/tests/helpers/yadda.js

@@ -1,2 +1,2 @@
-import yadda from 'npm:yadda';
-export default yadda;
+import yadda from 'yadda';
+export default yadda;