add partial sharing response example and schema

[butonic]

We should have a way to return errors for partially successful sharing requests. Follows ms graph https://learn.microsoft.com/en-us/graph/api/driveitem-invite?view=graph-rest-beta&tabs=http#partial-success-response

[butonic]

it is interesting to see that ms graph has two more properties:
one that contains a localized message that can be shown to the end user:

"localizedMessage": "Kontobestätigung erforderlich, um das Senden von E-Mails zu entsperren.",

Nothing for this PR, but this is how they move error localization to the server side.

And one that I assume is intendet to educate the end user.

"fixItUrl":"http://g.live.com/8SESkydrive/VerifyAccount",

In this case it is a link to the login page of onedrive.

Interestingly they have defined a list of errors clients should expect: https://learn.microsoft.com/en-us/graph/api/driveitem-invite?view=graph-rest-beta&tabs=http#sendnotification-errors

It seems they are running into exactly the same problem, even when they are 'just' trying to send out email and we are trying to persist perminssions in the share manager.

Oh and:

Note: The service can add new error codes or stop returning old ones at any time.