provide "dependency fulfilled" life cycle in order to avoid NPE on constructor

[k1r0s]

sample issue:

import { Provider, Dependency } from "@ritley/decorators";
import { OpcuaService } from "../services/opcua.service";
import { ConfigService } from "../services/config.service";

export { ApiModule }

@Provider.factory
@Dependency("client", OpcuaService)
@Dependency("config", ConfigService)
class ApiModule {

  values = null;

  // FIXME: ritley (lib) should provide "dependency fulfilled" life cycle in order to avoid this:
  constructor() {
    setTimeout(() => this.initialize(), 10);
  }

  initialize() {
    this.config.getContents().then(values => {
      this.values = values;
      this.start(this.values.address);
    })
  }

  async start(address) {
    await this.client.doConnect(address);
    await this.client.createSession();
  }

  browse(nodeId) {
    return this.client.browseChilds(nodeId || this.values.rootNode);
  }
}