Fixes #7950 - Show docker repos in a CV

Code to show docker information like

```
$ hammer content-view info --organization=docker --name=wow
ID:                  5
Name:                wow
Label:               wow
Composite:           
Description:         
Content Host Count:  0
Organization:        docker
Yum Repositories:    
 1) ID:    17
    Name:  zoo
    Label: zoo
Docker Repositories: 
 1) ID:    29
    Name:  fedora/rabbitmq
    Label: fedora_rabbitmq
Puppet Modules:      
 
Environments:        
 1) ID:   2
    Name: Library
Versions:            
 1) ID:        4
    Version:   1
    Published: 2014/10/10 19:14:30
 2) ID:        7
    Version:   2
    Published: 2014/10/10 20:31:58
 3) ID:        8
    Version:   3
    Published: 2014/10/14 19:43:49
Components:          
 
Activation Keys:
```
`extend_data` is the proper place for changing the data that's returned back to the server. `send_request` **can** be used to modify the returned data, but `extend_data` exists for that exact purpose.

Here's where `#extend_data(record)` is [defined](https://github.com/theforeman/hammer-cli-foreman/blob/master/lib/hammer_cli_foreman/commands.rb#L311-L313) and here's an example of another place [using it](https://github.com/Katello/hammer-cli-katello/blob/a30e87b47c7775aea3ad8feb1898f6c21748940a/lib/hammer_cli_katello/activation_key.rb#L122-L129). it exists for both `InfoCommand` as well as `ListCommand`.