Implement asynchronous injection with async factories

[basedalexander]

The idea is to add ability of injecting stuff asynchronously. The syntax example:

{ 
      token: 'IConfig',
      useFactory: async (service: any) => {
              const something = await.service.getSomething();
              return something;
      },
     inject: [Service]
}

[andrei-tatar]

Does that mean resolve would always return a promise?
Or do you plan on adding a resolveAsync (in which case the consumer should know if the dependencies are resolved asyn)?