Description of problem:
Report template information does not include 'Locked' attribute.

How reproducible:
Always

Steps to Reproduce:
1. Fetch report template info using any method given below-

1. curl -X GET -k -u admin:<pwd> https://&lt;foreman-fqdn&gt;/api/report_templates/&lt;template-id> -H 'content-type: application/json'

OR

1. hammer report-template info --id <template-id>
   2. the output of above curl/hammer does not have the value for 'Locked' attribute.

Actual results:
curl/hammer command to get the report template info, does not have the value for 'Locked' attribute.

Expected results:
'Locked' attribute should be displayed through API request and hammer output.

Additional info:
- from the webUI, it can be checked if report template is locked or not.
- As a user, I may want to check if report template is locked or not from the API response or from the hammer output.
- like the output of `hammer template info --id <template-id>` it would be good to include the 'Locked' attribute for report template.