[ADF-5311] Extract infinite select scroll loading logic to a reusable component (#6536)

* move translation to core

* select scroll directive

* register directive

* add infinite scroll directive

* clean up component and aditional logic

* use  waitForAsync over async

* update docs

* change output emitter name

* revert to async

* restore default value;

* test

lib/core/i18n/en.json

@@ -529,5 +529,8 @@
     "BUTTON": {
       "ARIA_LABEL": "Clear"
     }
+  },
+  "ADF_DROPDOWN": {
+    "LOADING": "Loading..."
   }
 }