Add confirmation to modal before updating

[duncanmcclean]

This pull request adds a confirmation modal to the Statamic updater before the site begins to update. Closes #884.

[jasonvarga]

Thanks for the PR. A couple of things:

This component is used on the Statamic updater as well as for any addons. So as you have it now, when you try to upgrade an addon, it'll say "Are you sure you want to update Statamic?", but it's not Statamic.

Second, even when you're about to downgrade, the confirmation still asks if you want to update.

I think you can resolve both issues by making the message a bit more generic.

Are you sure you want to {update/downgrade} to {version}?

One way you could do that is to change confirmationOpen from a boolean to an object, and when you click a button, set the release to that. Then the confirmation can read the type and version.

[duncanmcclean]

Agreed. Those sound like some good changes. I'll try and make them tonight.

[jasonvarga]

I've slightly tweaked it so that the confirmation dialog is closed when you click confirm, instead of it sitting in the background. Otherwise, 👍

[duncanmcclean]

I've slightly tweaked it so that the confirmation dialog is closed when you click confirm, instead of it sitting in the background. Otherwise, 👍

Awesomeee!