Store data in browser with Indexeddb

[elie222]

We can store gigabytes of data in an indexddb in the browser.
Use idb package to do this.

The advantage here is extra privacy for users. After this is done we can remove large parts of the backend. The client can load the data itself and use the Gmail API to archive/label/reply.
It will also mean faster loading times.

The core tables to use are:

• Emails
• Labels

We may need more tables after for sorting in different ways, or to help with analytics.

[sharma-shanu]

@elie222 , Can you assign this task to me ?

[elie222]

Not relevant atm.