add functionality to delete employee button (#11)

Reviewed-on: #11
Reviewed-by: Hernd Beidemann <huydw@proton.me>

src/app/services/employee-api.service.ts

@@ -0,0 +1,22 @@
+import {inject, Injectable} from "@angular/core";
+import {HttpClient} from "@angular/common/http";
+import {Observable} from "rxjs";
+import {Employee} from "../Employee";
+
+
+@Injectable({
+  providedIn: 'root'
+})
+export default class EmployeeApiService {
+  private http: HttpClient = inject(HttpClient);
+
+  private static readonly BASE_URL = 'http://localhost:8089';
+
+  public deleteById(id: number): Observable<Employee> {
+    return this.http.delete(`${EmployeeApiService.BASE_URL}/employees/${id}`)
+  }
+
+  public getAll(): Observable<Employee[]> {
+    return this.http.get<Employee[]>(`${EmployeeApiService.BASE_URL}/employees`)
+  }
+}