[OCIS] groups not returned in Sharees endpoint

[dpakach]

steps to reproduce

1. Create a group richard
2. Try to get the sharees using the sharees endpoint

expected

should give user richard and group richard

Actual

only returns user richard

curl https://localhost:9200/ocs/v2.php/apps/files_sharing/api/v1/sharees\?search\=rich\&format\=json -k -u moss:vista | jq
% Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   228  100   228    0     0   1664      0 --:--:-- --:--:-- --:--:--  1652
{
  "ocs": {
    "meta": {
      "status": "ok",
      "statuscode": 200,
      "message": "OK"
    },
    "data": {
      "exact": {
        "users": [],
        "groups": [],
        "remotes": []
      },
      "users": [
        {
          "label": "Richard Feynman",
          "value": {
            "shareType": 0,
            "shareWith": "richard"
          }
        }
      ],
      "groups": [],
      "remotes": []
    }
  }
}