feat: use localstorage instead of url params for yarn checkbox

[Sacquer]

Summary

Make use of localstorage to save state for the yarn checkbox.
In an earlier revision the state for the yarn checkbox was making use of url params - that part has been removed.

Test Plan

What are the steps to reproduce?

Open up your devtools and check the values getting toggled under the key backstage:upgrade-helper:settings in localstorage. The changes will also be reflected in the ui.

Checklist

• I tested this thoroughly
• I added the documentation in README.md (if needed)

[Sacquer]

Changes originated from this discord thread

[vinzscam]

mmm then state won't persist when the link is shared and also this in the cli bump command will break

[Sacquer]

mmm then state won't persist when the link is shared and also this in the cli bump command will break

Thanks for replying so quickly!
I see it's not as straightforward as I thought it'd be ☺️ - or rather it might not make much sense to remove the url params way of persisting things.

I guess the question is if we should scrap it or check localstorage for value and populate url params?

[vinzscam]

mmm then state won't persist when the link is shared and also this in the cli bump command will break

Thanks for replying so quickly! I see it's not as straightforward as I thought it'd be ☺️ - or rather it might not make much sense to remove the url params way of persisting things.

I guess the question is if we should scrap it or check localstorage for value and populate url params?

I think it's pretty straightforward @Sacquer if you wanna have a look again! What we basically want is that if no yarnPlugin query param is defined, we read the preference localstorage and add the missing queryParam to the url. The preferences are already stored in localStorage.