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>

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

@@ -27,7 +27,7 @@
             top: 0;
             right: 0;
             color: #aaaaaa;
-            padding: .4em;
+            padding: .3em;
     
             &:hover {
                 background-color: #eee;

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

@@ -1,6 +1,6 @@
-import { HttpParams } from "@angular/common/http";
 import { Component, inject } from "@angular/core";
 import { FormBuilder, FormControl, ReactiveFormsModule, Validators } from "@angular/forms";
+import { MatRippleModule } from "@angular/material/core";
 import { MatIconModule } from "@angular/material/icon";
 import { Router } from "@angular/router";
 
@@ -11,8 +11,9 @@ import { Router } from "@angular/router";
     styleUrl: './publications-search-bar.component.scss',
     standalone: true,
     imports: [
-        ReactiveFormsModule,
-        MatIconModule
+        MatIconModule,
+        MatRippleModule,
+        ReactiveFormsModule
     ],
     providers: []
 })