Add submit button component and style it.

frontend/src/app/components/submit-button/submit-button.component.ts

@@ -0,0 +1,20 @@
+import { CommonModule } from "@angular/common";
+import { Component, EventEmitter, Input, Output } from "@angular/core";
+import { MatProgressSpinnerModule } from "@angular/material/progress-spinner";
+
+
+@Component({
+    selector: 'app-submit-button',
+    standalone: true,
+    imports: [MatProgressSpinnerModule, CommonModule],
+    templateUrl: 'submit-button.component.html',
+    styleUrl: 'submit-button.component.scss'
+})
+export class SubmitButtonComponent {
+    @Input() requestPending: boolean = false;
+    @Input() label: string = '';
+    @Input() disabled: boolean = false;
+    @Input() color?: 'secondary';
+    @Output() click = new EventEmitter<void>();
+  }
+