Add order and performance info components to ticket overlay

Introduces OrderComponent, PerformanceInfoComponent, and ShoppingCartComponent for the ticket purchase flow. Updates theater-overlay to display seat selection alongside order details and performance info. Refactors seat and performance data loading, improves UI structure, and enhances movie info display components for consistency.

src/app/order/order.component.html

@@ -0,0 +1,49 @@
+<div class="w-full h-full">
+  <mat-stepper
+    orientation="horizontal"
+    linear="true"
+    #stepper
+  >
+    <mat-step [stepControl]="firstFormGroup">
+      <form [formGroup]="firstFormGroup">
+        <ng-template matStepLabel>Warenkorb</ng-template>
+
+        @if (performance()) {
+          <app-performance-info class="w-full h-50" [performance]="performance()!"></app-performance-info>
+        }
+
+        <div>
+          <button mat-button matStepperNext>Next</button>
+        </div>
+      </form>
+    </mat-step>
+
+    <mat-step [stepControl]="secondFormGroup">
+      <form [formGroup]="secondFormGroup">
+        <ng-template matStepLabel>Anschrift</ng-template>
+        <mat-form-field>
+          <mat-label>Address</mat-label>
+          <input
+            matInput
+            formControlName="secondCtrl"
+            placeholder="Ex. 1 Main St, New York, NY"
+            required
+          />
+        </mat-form-field>
+        <div>
+          <button mat-button matStepperPrevious>Back</button>
+          <button mat-button matStepperNext>Next</button>
+        </div>
+      </form>
+    </mat-step>
+-
+    <mat-step>
+      <ng-template matStepLabel>Zahlung</ng-template>
+      <p>You are now done.</p>
+      <div>
+        <button mat-button matStepperPrevious>Back</button>
+        <button mat-button (click)="stepper.reset()">Reset</button>
+      </div>
+    </mat-step>
+  </mat-stepper>
+</div>