Refactor to remove "Async" function name suffix

Remove convention where Async suffix is added to functions that returns
a Promise. It was a habit from C#, but is not widely used in JavaScript
/ TypeScript world, also bloats the code. The code is more consistent
with third party dependencies/frameworks without the suffix.

src/application/IApplicationFactory.ts

@@ -1,5 +1,5 @@
 import { IApplication } from '@/domain/IApplication';
 
 export interface IApplicationFactory {
-    getAppAsync(): Promise<IApplication>;
+    getApp(): Promise<IApplication>;
 }