Handle local storage quota exceeding error

[microbit-grace]

The following error can occur when users import a large hex / large number of data samples, adding action / data samples, or when adding to their MakeCode project:

QuotaExceededError: Failed to execute 'setItem' on 'Storage': Setting the value of 'ml' exceeded the quota.

To mitigate the issue, I have proposed adding a dialog to handle the error.

[github-actions]

Preview build will be at
https://review-createai.microbit.org/storage-quota/

[microbit-grace]

Large data samples json that can be used for testing:
too-many-samples.json

[microbit-grace]

Not sure if this is the best way of triggering the dialog, but thought it was the easiest way to wrap all the set actions in the store. Otherwise, I could write a wrapper to wrap state changes with a try-catch statement for catching quota exceeded errors, which I think is the more straightforward approach.

[microbit-matt-hillsdon]

I'm unsure whether error handling is the right route, or at least unsure if it should be the primary way to address the issue.

Other options we can consider:

• figure out practical limits (we know it's Edge/Chrome so likely 5MB - but check!) and impose restrictions on actions/samples that ensure we stay below
• potentially, we could store action data in a more compact format, but still in local storage
• if we really think folks have usecases for this then local storage is likely the wrong approach to persistence at least for the actions - IndexedDB has a higher limit I think

I'd like to understand more about what folks who hit this error are actually doing and whether it makes any sense in a tool like CreateAI.