Feature: Lazy loading

Lazy loaded everything
TODO: The cash flow module when clicking on sub-links, it reloads the whole page, it needs to be diagnosed and fixed, this problem also exists in the other modules
TODO: Rename folders and modules such as account to accounts to match the url

overlord/src/app/core/batch.service.ts

@@ -0,0 +1,24 @@
+import {Injectable} from '@angular/core';
+import {Observable} from 'rxjs/internal/Observable';
+import {catchError} from 'rxjs/operators';
+import {HttpClient, HttpParams} from '@angular/common/http';
+import {Batch} from './voucher';
+import {ErrorLoggerService} from './error-logger.service';
+
+const url = '/api/batch';
+const serviceName = 'BatchService';
+
+@Injectable({providedIn: 'root'})
+export class BatchService {
+
+  constructor(private http: HttpClient, private log: ErrorLoggerService) {
+  }
+
+  autocomplete(date: string, term: string): Observable<Batch[]> {
+    const options = {params: new HttpParams().set('t', term).set('d', date)};
+    return <Observable<Batch[]>>this.http.get<Batch[]>(url, options)
+      .pipe(
+        catchError(this.log.handleError(serviceName, 'autocomplete'))
+      );
+  }
+}