feat(material-experimental/mdc-slider): implement the SliderAdapter (#21844)

* feat(material-experimental/mdc-slider): implement the SliderAdapter

* complete the core logic for MatSliderThumb and MatSlider
* collapse slider-thumb.ts and slider-adapter.ts into slider.ts

Author: wagnermaciel

src/dev-app/mdc-slider/mdc-slider-demo.html

@@ -0,0 +1,4 @@
+<mat-slider min="-5" max="0" discrete showTickMarks>
+  <input matSliderStartThumb>
+  <input matSliderEndThumb>
+</mat-slider>

src/material-experimental/mdc-slider/module.ts

@@ -9,8 +9,7 @@
 import {CommonModule} from '@angular/common';
 import {NgModule} from '@angular/core';
 import {MatCommonModule} from '@angular/material-experimental/mdc-core';
-import {MatSlider} from './slider';
-import {MatSliderThumb} from './slider-thumb';
+import {MatSlider, MatSliderThumb} from './slider';
 
 @NgModule({
   imports: [MatCommonModule, CommonModule],

src/material-experimental/mdc-slider/public-api.ts

@@ -6,6 +6,5 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-export {MatSlider} from './slider';
-export {MatSliderThumb} from './slider-thumb';
+export {MatSlider, MatSliderThumb, MatSliderDragEvent} from './slider';
 export {MatSliderModule} from './module';

src/material-experimental/mdc-slider/slider-adapter.ts

@@ -16,9 +16,7 @@
 <div class="mdc-slider__thumb" *ngFor="let thumb of _getThumbTypes()" #thumb>
   <div class="mdc-slider__value-indicator-container" *ngIf="discrete">
     <div class="mdc-slider__value-indicator">
-      <span class="mdc-slider__value-indicator-text">
-        {{_getValueIndicatorTextByThumb(thumb)}}
-      </span>
+      <span class="mdc-slider__value-indicator-text">{{_getValueIndicatorText(thumb)}}</span>
     </div>
   </div>
   <div class="mdc-slider__thumb-knob" #knob></div>

src/material-experimental/mdc-slider/slider-thumb.ts

@@ -0,0 +1,6 @@
+@import '@material/slider/slider';
+@include core-styles;
+
+.mdc-slider {
+  display: block;
+}