Description of problem:
Below API endpoint-

/katello/api/v2/organizations/1/content_views?search=label=<cv_label>

should return the results based on the matched content view label.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
$ curl -k -u admin:ranjan -X GET 'https://<satellite-fqdn>/katello/api/v2/organizations/<org-id>/content_views?search=label=<label-name>' -H 'content-type: application/json'

webUI also does not provide 'label' as a searchable attribute.
Actual results:
API call shows the below error-

{"displayMessage":"undefined method `composite?' for 27:Fixnum","errors":["undefined method `composite?' for 27:Fixnum"]}

Expected results:

content view search should match the provided label and results the matched content views

Additional info: