Ability to opt out of subscription pre-renewal notifications

### What

The ability of a user to disable subscription renewal notifications.
When it's time for subscription renewals we send an email a few days/week before the due date.

A user is complaining that they are getting too many emails and would like these subscription notification emails turned off as they already have auto-renewal set up.

### Why

This would give the user the option to opt-out of these emails which would be on by default for every user. So only those who don't want to get these emails will disable them. just like we have for other email notification settings.

### How

Under https://wordpress.com/me/notifications/, we could have another tab titled subscriptions that would give the user the ability to opt out of subscription-related emails like the pre-renewal notification emails.

The checkmark could also only be active if the user has an active/auto-renewable paid subscription.

Start at the notifications page linked in the issue and trace how subscription-related notification preferences and pre-renewal emails are represented. Confirm how active or auto-renewable paid subscriptions affect the control, then verify that the preference is enabled by default and that opting out prevents the specified emails.

Written by the indexing model from the issue text.