start of caching, csrf interceptor, and device service

src/app/http-interceptors/index.ts

@@ -0,0 +1,8 @@
+/* "Barrel" of Http Interceptors */
+import { HTTP_INTERCEPTORS } from '@angular/common/http';
+import { CSRFInterceptor } from './csrf-intercepor';
+
+/** Http interceptor providers in outside-in order */
+export const httpInterceptorProviders = [
+    { provide: HTTP_INTERCEPTORS, useClass: CSRFInterceptor, multi: true },
+];