Remove select2 from vendored

* Make core/utils/select2.ts
* Convert viewer-index.js to typescript

tsconfig.json

@@ -7,6 +7,7 @@
     "target": "es5",
     "allowJs": true,
     "moduleResolution": "node",
+    "types": ["jquery", "alpinejs"],
     "paths": {
       "#openapi": ["./staticfiles/generated/openapi/index.ts"],
       "#core:*": ["./core/static/webpack/*"],