title: FontAwesome Icons Not showing up when used with PrimeNg Module
body: <p>I have installed angular-fontawesome using the instructions here:
  <a href="https://www.npmjs.com/package/@fortawesome/angular-fontawesome" rel="nofollow noreferrer">https://www.npmjs.com/package/@fortawesome/angular-fontawesome</a></p>
  
  <p>The icons show up when used in this fashion (app.component.html):</p>
  
  <pre><code>    &lt;div style="text-align:center"&gt;
          &lt;!-- simple name only that assumes the 'fas' prefix --&gt;
          &lt;fa-icon icon="coffee"&gt;&lt;/fa-icon&gt;
          &lt;!-- ['fas', 'coffee'] is an array that indicates the [prefix, iconName] --&gt;
          &lt;fa-icon [icon]="['fas', 'coffee']"&gt;&lt;/fa-icon&gt;
          &lt;fa-icon [icon]="['fa', 'fa-fw', 'fa-book']"&gt;&lt;/fa-icon&gt;
        &lt;/div&gt;
  </code></pre>
  
  <p>My app.module.ts</p>
  
  <pre><code>import { BrowserModule } from '@angular/platform-browser';
  import {BrowserAnimationsModule} from '@angular/platform-browser/animations';
  import { NgModule } from '@angular/core';
  import { HttpClientModule } from '@angular/common/http';
  
  import { AppRoutingModule } from './app-routing.module';
  import { AppComponent } from './app.component';
  
  import { ButtonModule } from 'primeng/button';
  import { MenuModule } from 'primeng/menu';
  import { TabMenuModule } from 'primeng/tabmenu';
  import { FontAwesomeModule } from '@fortawesome/angular-fontawesome';
  import { library } from '@fortawesome/fontawesome-svg-core';
  import { fas } from '@fortawesome/free-solid-svg-icons';
  import { far } from '@fortawesome/free-regular-svg-icons';
  
  import { TestcomponentComponent } from './testcomponent/testcomponent.component';
  
  @NgModule({
    declarations: [
      AppComponent,
      TestcomponentComponent
    ],
    imports: [
      BrowserModule,
      BrowserAnimationsModule,
      AppRoutingModule,
      HttpClientModule,
      ButtonModule,
      MenuModule,
      TabMenuModule,
      FontAwesomeModule,
    ],
    providers: [],
    bootstrap: [AppComponent]
  })
  export class AppModule { 
    constructor() {
          // Add an icon to the library for convenient access in other components
          library.add(fas, far);
    }
  }
  </code></pre>
  
  <p>However, I get no icons when integrating it with a PrimeNg Module (in this case their TabMenuModule). Not doing anything unusual, just following the instructions here:
  <a href="https://www.primefaces.org/primeng/#/tabmenu" rel="nofollow noreferrer">https://www.primefaces.org/primeng/#/tabmenu</a></p>
  
  <pre><code>app.component.ts
  export class AppComponent {
    title = 'ClientApp';
  
    private items: MenuItem[];
  
          ngOnInit() {
            this.items = [
              {label: 'Overview', icon: 'fa fa-fw fa-bar-chart'},
              {label: 'Schedule', icon: 'fa fa-fw fa-calendar'},
              {label: 'Documentation', icon: 'fa-coffee'},
              {label: 'Support', icon: 'fa fa-fw fa-support'},
              {label: 'Discussion', icon: 'fa fa-fw fa-twitter'}
          ];
        }
  </code></pre>
  
  <p>I add these lines to top of the html:</p>
  
  <pre><code>&lt;h3 class="first"&gt;Default&lt;/h3&gt;
      &lt;p-tabMenu [model]="items1" [activeItem]="items1[0]"&gt;&lt;/p-tabMenu&gt;
  
      &lt;h3&gt;Templating&lt;/h3&gt;
      &lt;p-tabMenu [model]="items2" [activeItem]="activeItem"&gt;
          &lt;ng-template pTemplate="item" let-item let-i="index"&gt;
              &lt;div style="position: relative; text-align: center; min-width: 10em"&gt;
                  &lt;div class="ui-menuitem-icon" [ngClass]="item.icon" *ngIf="item.icon" style="font-size: 2em"&gt;&lt;/div&gt;
                  &lt;div class="ui-menuitem-text"&gt;
                      {{item.label}}
                  &lt;/div&gt;
                  &lt;a tabindex="0" class="ui-menuitem-icon" (click)="closeItem($event, i)" style="position: absolute; right: -1em; top: -.5em; padding: 0" *ngIf="i !== 0"&gt;
                      &lt;span class="pi pi-times"&gt;&lt;/span&gt;
                  &lt;/a&gt;
              &lt;/div&gt;
          &lt;/ng-template&gt;
      &lt;/p-tabMenu&gt;
  &lt;p-tabMenu [model]="items"&gt;&lt;/p-tabMenu&gt;
  &lt;i class="far fa-chart-bar"&gt;&lt;/i&gt;
  </code></pre>
  
  <p>angular.json:</p>
  
  <pre><code>"build": {
            "builder": "@angular-devkit/build-angular:browser",
            "options": {
              "outputPath": "dist/ClientApp",
              "index": "src/index.html",
              "main": "src/main.ts",
              "polyfills": "src/polyfills.ts",
              "tsConfig": "src/tsconfig.app.json",
              "assets": [
                "src/favicon.ico",
                "src/assets"
              ],
              "styles": [
                "node_modules/primeicons/primeicons.css",
                "node_modules/primeng/resources/themes/nova-light/theme.css",
                "node_modules/primeng/resources/primeng.min.css",
                "src/styles.css"
              ],
  </code></pre>
  
  <p>I am using: 
  Angular CLI: 8.0.2
  Node: 10.15.3
  OS: win32 x64
  Angular: 8.0.0
  angular-fontawesome@0.4.0
  free-solid-svg-icons@5.9.0
  free-regular-svg-icons@5.9.0</p>