Graph API should return full content when Patching with Prefer header: return=representation

When patching a user (and probably many other things), the Graph API will always return 204 No Content, even when adding the header Prefer: return=representation.

This however is not following the https://docs.oasis-open.org/odata/odata/v4.01/odata-v4.01-part1-protocol.html#sec_Preferencereturnrepresentationandret.

This issue was started on GitHub here: https://github.com/microsoftgraph/msgraph-sdk-dotnet/issues/1682