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/core/http/api-prefix.interceptor.spec.ts

@@ -2,7 +2,7 @@ import { TestBed, inject } from '@angular/core/testing';
 import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';
 import { HTTP_INTERCEPTORS, HttpClient } from '@angular/common/http';
 
-import { environment } from '@env/environment';
+import { environment } from '../../../environments/environment';
 import { ApiPrefixInterceptor } from './api-prefix.interceptor';
 
 describe('ApiPrefixInterceptor', () => {

src/app/core/http/api-prefix.interceptor.ts

@@ -1,5 +1,6 @@
 import { Injectable } from '@angular/core';
 import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest } from '@angular/common/http';
+
 import { Observable } from 'rxjs';
 
 import { environment } from '../../../environments/environment';

src/app/core/http/cache.interceptor.ts

@@ -1,5 +1,6 @@
 import { Injectable } from '@angular/core';
 import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest, HttpResponse } from '@angular/common/http';
+
 import { Observable, Subscriber } from 'rxjs';
 
 import { HttpCacheService } from './http-cache.service';

src/app/core/http/error-handler.interceptor.ts

@@ -1,5 +1,6 @@
 import { Injectable } from '@angular/core';
 import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest } from '@angular/common/http';
+
 import { Observable } from 'rxjs';
 import { catchError } from 'rxjs/operators';
 

src/app/core/http/http-cache.service.ts

@@ -1,5 +1,6 @@
 import { Injectable } from '@angular/core';
 import { HttpResponse } from '@angular/common/http';
+
 import { each } from 'lodash';
 
 import { Logger } from '../logger.service';

src/app/core/http/http.service.ts

@@ -1,5 +1,6 @@
 import { Inject, Injectable, InjectionToken, Injector, Optional } from '@angular/core';
 import { HttpClient, HttpEvent, HttpInterceptor, HttpHandler, HttpRequest } from '@angular/common/http';
+
 import { Observable } from 'rxjs';
 
 import { ErrorHandlerInterceptor } from './error-handler.interceptor';