[Console Monaco migration] Save and restore editor folds from localStorage

[yuliacech]

When a user folds editor lines in Ace, their state is persisted in localStorage. We need to re-implement the same for monaco

[elasticmachine]

Pinging @elastic/kibana-management (Team:Kibana Management)

[ElenaStoeva]

I didn't see anything in the Monaco documentation for setting/retrieving folds and experimented with different APIs but no luck so far.

I found this issue in the Monaco repo where the author overall wants to do the same thing as we do, and the Monaco team has suggested a way for setting folds, but it doesn't use a public API so it might be unreliable. Also, they have mentioned that there's no way to obtain the folds in the editor, which is a problem for us since we need to retrieve the folds in order to store them. There is another open Monaco issue for catching a fold change event but again there is no straightforward solution and the proposed approach is pretty hacky.

With that being said, we might need to reconsider whether it is worth keeping this functionality given that it's not that important and its implementation would be very complex.

[yuliacech]

Thanks a lot for researching this feature, @ElenaStoeva!
I agree with your assessment, let's confirm in the team sync today

[yuliacech]

As discussed with the team, I'm closing this issue: we won't implement persisting the folded ranges in localStorage