Recipients user and group with same name

[jesmrec]

Check the following steps:

1. Create a user called peter
2. Create a group called peter
3. User mary shares something with user peter (correct sharing)
4. User mary tries to share something with group peter

Current: group peter is not listed as matching option (because peter is already a recipient, i guess)

Expected: even when a user and a group have the same name, they are different recipients. It should be allowed to share with both.

Reference: owncloud/core#35488