feat(frontend): modernize Angular app

ui/src/app/components/slave-checkbox.component.ts

@@ -0,0 +1,22 @@
+import { Component, input } from '@angular/core';
+import { MasterCheckboxComponent } from './master-checkbox.component';
+import { Checkable } from '../interfaces';
+import { FormsModule } from '@angular/forms';
+
+@Component({
+    selector: 'app-slave-checkbox',
+    template: `
+  <div class="form-check">
+    <input type="checkbox" class="form-check-input" id="{{master().id()}}-{{id()}}-select" [(ngModel)]="checkable().checked" (change)="master().selectionChanged()">
+    <label class="form-check-label" for="{{master().id()}}-{{id()}}-select"></label>
+  </div>
+`,
+imports: [  
+  FormsModule
+]
+})
+export class SlaveCheckboxComponent {
+  readonly id = input.required<string>();
+  readonly master = input.required<MasterCheckboxComponent>();
+  readonly checkable = input.required<Checkable>();
+}