feat: add app shell (angular-material)

Add app shell built using angular-material and flex-layout. Refractor
code due to configuration changes.

Fixes #52

src/app/login/login.module.ts

@@ -1,6 +1,7 @@
 import { NgModule } from '@angular/core';
 import { CommonModule } from '@angular/common';
 import { ReactiveFormsModule } from '@angular/forms';
+
 import { TranslateModule } from '@ngx-translate/core';
 
 import { LoginRoutingModule } from './login-routing.module';