feat: show snackbar if no data connection in shared deck download

[criticalAY]

Purpose / Description

Dont open the webview in case no network is detected and show a snackbar instead

How Has This Been Tested?

Locally API 35

Checklist

Please, go through these checks before submitting the PR.

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[david-allison]

This looks good.

A HUGE win would be to introduce this while syncing. We previously had really good online/offline detection, but this was lost on the upgrade of the sync code to use the new backend

[BrayanDSO]

Same request of David

[david-allison]

I don't believe I have a request here which warrants an author reply. I'd rather a new issue/PR rather than 'piling on' to this PR with a larger request

I've clarified my comment, which was intended as documentation, rather than a request

[criticalAY]

Can we remove the author reply label