Description of problem:
Ceph dashboard cli commands returns in same format even though requested for different format using '-f' argument.
It would be nice if we can provide an option to check information in user required format 
Example json-pretty

Version-Release number of selected component (if applicable):
16.2.0-81.el8cp

How reproducible:
Always

Steps to Reproduce:
1. Configure a RHCS cluster
2.
3.

Actual results:
[root@e16-h18-b01-fc640 /]# ceph dashboard ac-user-show admin123 -f json-pretty

{"username": "admin123", "password": "$2b$12$L7NX2D9sBxhY.tgZk0Y0a.7py3jIhVPf6TY/6Fq8JkHMxH.beEjQ.", "roles": ["administrator"], "name": null, "email": null, "lastUpdate": 1624621239, "enabled": true, "pwdExpirationDate": null, "pwdUpdateRequired": false}
[root@e16-h18-b01-fc640 /]# ceph dashboard ac-user-show admin123 -f xml        
{"username": "admin123", "password": "$2b$12$L7NX2D9sBxhY.tgZk0Y0a.7py3jIhVPf6TY/6Fq8JkHMxH.beEjQ.", "roles": ["administrator"], "name": null, "email": null, "lastUpdate": 1624621239, "enabled": true, "pwdExpirationDate": null, "pwdUpdateRequired": false}

Expected results:
Try to retrieve information in json-pretty format from ceph dashboard commands

Additional info: