Chore: Check for deprecations using eslint plugin

Chore: environment file replacement stopped.
Chore: All components are now standalone and removed all modules
Chore: App routing is now in app.routes and similarly for all submodules
Chore: Http interceptors are now functional and split refresh interceptor into a separate one.

overlord/src/app/period/period-list/period-list.component.spec.ts

@@ -1,6 +1,4 @@
 import { ComponentFixture, fakeAsync, TestBed } from '@angular/core/testing';
-import { ReactiveFormsModule } from '@angular/forms';
-import { RouterTestingModule } from '@angular/router/testing';
 
 import { PeriodListComponent } from './period-list.component';
 
@@ -10,8 +8,7 @@ describe('PeriodListComponent', () => {
 
   beforeEach(fakeAsync(() => {
     TestBed.configureTestingModule({
-      imports: [ReactiveFormsModule, RouterTestingModule],
-      declarations: [PeriodListComponent],
+      imports: [ReactiveFormsModule, RouterTestingModule, PeriodListComponent],
     }).compileComponents();
 
     fixture = TestBed.createComponent(PeriodListComponent);