Backup, restore and export contact photo

[meain]

Photos of exchange contacts are currently not backed up. We will have to do a separate request for each contact and store the data separately.

• GET https://graph.microsoft.com/:version/users/:user/contacts/:contact-id/photo gets the contact photo metadata
• GET https://graph.microsoft.com/:version/users/:user/contacts/:contact-id/photo/$value gets the actual contact photo