Use async functions instead of promises

[mrts]

Overview of the feature request

Use async/await instead of promises for more succinct code.

For example, instead of the following JHipster-generated code

    this.rideService()
      .retrieve(paginationQuery)
      .then(
        res => {
          this.rides = res.data;
          this.totalItems = Number(res.headers['x-total-count']);
          this.queryCount = this.totalItems;
          this.isFetching = false;
        },
        err => {
          this.isFetching = false;
        }
      );

do this:

  try {
    const res = await this.rideService().retrieve(paginationQuery);
    this.rides = res.data;
    this.totalItems = Number(res.headers['x-total-count']);
    this.queryCount = this.totalItems;
  } finally {
    this.isFetching = false;
  }

Note that I've left out catch for purely aesthetic reasons - it is still actually required.

Motivation for or Use Case

Quoting Google Developers async functions primer:

Async functions are [...] quite frankly marvelous. They allow you to write promise-based code as if it were synchronous, but without blocking the main thread. They make your asynchronous code less "clever" and more readable.

---

• Checking this box is mandatory (this is just to show you read everything)

[atomfrede]

Seems like a good idea. Would you mind doing a PR for that? @jhipster/vuejs-developers wdyt?

[mrts]

Possibly - let's see how far I get

[antonioortizpola]

@mrts have you found time to work on this?

If not, I could take it to work with in the next one or two weeks.

[pascalgrimaud]

I don't know Vue.js enough to tell if it's the right way or not.
Cc @sahbi-ktifa @hdurix @nonomoho : I need your opinion here
Maybe @Gnuk you can help too ? What do you think

[nonomoho]

I discussed it with @Gnuk:
Both solutions are good but we don't like try/catch so much ...

[mrts]

@antonioortizpola nope, sorry, I don't currently have time. Please go ahead - and good luck :)! Note that you have to use try/catch, try/finally is incomplete.

[mrts]

@nonomoho glad you like this, but can you elaborate why you don't like try/catch?

[nonomoho]

It's juste personal, I think then syntax is more understandable!
But it's just my opinion 😉

[antonioortizpola]

Coming from C# await seems way more natural to me, what is the "standard" or the more used way in JS and Vue?