Add ripple everywhere.

frontend/src/app/components/publications-search-bar/publications-search-bar.component.html

@@ -1,6 +1,6 @@
 <form [formGroup]="formGroup">
     <input name="search-query" placeholder="Search something..." formControlName="criteria" i18n-placeholder/>
-    <button type="submit" (click)="searchPublications()">
+    <button type="submit" (click)="searchPublications()" matRipple>
         <mat-icon>search</mat-icon>
     </button>
 </form>