Under permissions for shared calendars, it needs a few more options.

Currently when sharing with other proton users there is only:
- View only
- view and edit

We need a few more options:
- View as free/busy (contents hidden, only time blocks visible)
- View all details (standard view only)
- View and Edit (able to view and edit/create/delete events)
- view, edit, and manage sharing (able to view, edit/create/delete events, and manage sharing - invite, remove, etc - of calendar)

This beneficial for individuals, freelancers, businesses, families, etc.