♻️🐛 [Frontend] Reuse iframe starting sequence for guests

[odeimaiz]

What do these changes do?

The Dynamic Service starting sequence (poll state, show loading sequence, handle errors, switch to iframe's content...) wasn't the same for logged in users and guest users. This PR unifies the code related to it.

Bonus: Switch to Voila loading content, instead of staying at the Ready loading page, without waiting for the native "load" event.

@Konohana0608 I also found the way to tune the Running 2 of 5... loading voila message. Notice the Sleeping for 30" message:

Related issue/s

How to test

Dev-ops checklist

• [ ] No ENV changes or I properly updated ENV (read the instruction)

[odeimaiz]

Very nice, thanks! I also want to see the trick to tune the voila loading messages. 🤩

@elisabettai

Add the following cell before running the cell that is going to take long

%%js
const loadingTextEl = document.getElementById("loading_text");
loadingTextEl ? loadingTextEl.innerText = 'This task is going to take very long' : null;

Here we just change the text, but you could also add some fancy HTML 👌