[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

docs/core/directives/infinite-select-scroll.directive.md

@@ -0,0 +1,30 @@
+---
+Title: Infinite Select Scroll directive
+Added: v4.3.0
+Status: Active
+Last reviewed: 2020-01-14
+---
+
+# [Infinite Select Scroll](../../../lib/core/directives/infinite-select-scroll.directive.ts "Defined in infinite-select-scroll.directive.ts")
+
+Load more options to select component if API returns more items
+
+## Basic Usage
+
+```html
+<mat-select
+    adf-infinite-select-scroll
+    (scrollEnd)="load()">
+    <mat-option *ngFor="let option of options">
+        {{ option }}
+    </mat-option>
+</mat-select>`
+```
+
+## Class members
+
+### Events
+
+| Name | Type | Description |
+| --- | --- | --- |
+| scrollEnd | [`EventEmitter`](https://angular.io/api/core/EventEmitter)`<`[`Event`](https://developer.mozilla.org/en-US/docs/Web/API/Event)`>` | Emitted when scroll reaches the last item. |