[Cashtab] [notification permission 1 of 2] Ask for notification permission if peristent storage is not granted

Summary:
T2882

Testing shows that persistent storage will be granted in Brave browser if the user approves the notification permission.

This diff asks for notification permission if the persistent storage permission is not granted and the user has not already granted notification permission.

Test Plan:
npm run build
netlify deploy

Open the URL netlify has deployed to and check the dev console. You should see Persisted storage status: false. In this case, the app will load instantly with a pop-up asking you to enable notification permissions. Enable.

Refresh the page.
Create a wallet.
Refresh the page.

You should see Persisted storage status: true

Check in Brave, Chrome, and Safari

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Subscribers: emack

Differential Revision: https://reviews.bitcoinabc.org/D12905