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/account.ts

@@ -0,0 +1,18 @@
+import {AccountType} from './account-type';
+import {CostCentre} from './cost-centre';
+
+export class Account {
+  id: string;
+  code: number;
+  name: string;
+  type: AccountType;
+  isActive: boolean;
+  isReconcilable: boolean;
+  isStarred: boolean;
+  isFixture: boolean;
+  costCentre: CostCentre;
+
+  public constructor(init?: Partial<Account>) {
+    Object.assign(this, init);
+  }
+}