Capability of marking some actions as hidden

Enhancement Request:

It would be good to have capability of marking some actions in an integration pack as hidden so that they exist (and are used in action chains or mistral workflow tasks) but are not shown in the action list for the pack from the CLI or UI. Intention behind this is to avoid the end user directly calling these actions as their usage primarily confined from inside the workflows. Here, the workflows will be exposed to the user to execute.

Example:

In this mistral workflow, actions vslx.vslx_set_linecards and vslx.vslx_add_static_mgmt_ip are ideally not to be exposed to the end user, and should be called from the workflows only.

+--------------------------+--------------------------+----------------------------+----------------------------+------------------------------+
| id                       | status                   | task                       | action                     | start_timestamp              |
+--------------------------+--------------------------+----------------------------+----------------------------+------------------------------+
| 58de2df4e79fa005d2085678 | succeeded (1s elapsed)   | install_pwdless_ssh_depend | core.local_sudo            | Fri, 31 Mar 2017 10:22:44    |
|                          |                          | ency                       |                            | UTC                          |
| 58de2df5e79fa005d208567a | succeeded (0s elapsed)   | set_root_known_hosts       | core.local_sudo            | Fri, 31 Mar 2017 10:22:45    |
|                          |                          |                            |                            | UTC                          |
| 58de2df7e79fa005d208567c | succeeded (0s elapsed)   | set_stanley_known_hosts    | core.local                 | Fri, 31 Mar 2017 10:22:47    |
|                          |                          |                            |                            | UTC                          |
| 58de2df8e79fa005d208567e | succeeded (1s elapsed)   | config_pwdless_ssh         | core.local                 | Fri, 31 Mar 2017 10:22:48    |
|                          |                          |                            |                            | UTC                          |
| 58de2dfae79fa005d2085680 | succeeded (1s elapsed)   | set_linecards_string       | vslx.vslx_set_linecards    | Fri, 31 Mar 2017 10:22:50    |
|                          |                          |                            |                            | UTC                          |
| 58de2dfbe79fa005d2085682 | succeeded                | create_new_chassis         | core.remote                | Fri, 31 Mar 2017 10:22:51    |
|                          | (1441s elapsed)          |                            |                            | UTC                          |
| 58de33a0e79fa005d2085684 | succeeded (2s elapsed)   | power_on_chassis           | core.remote                | Fri, 31 Mar 2017 10:46:56    |
|                          |                          |                            |                            | UTC                          |
| 58de33a2e79fa005d2085686 | succeeded (748s elapsed) | add_mgmt_ip_to_chassis     | vslx.vslx_add_static_mgmt_ | Fri, 31 Mar 2017 10:46:58    |
|                          |                          |                            | ip                         | UTC                          |
+--------------------------+--------------------------+----------------------------+----------------------------+------------------------------+

Start by tracing how integration-pack actions are enumerated for the CLI and UI, then inspect how Mistral workflow tasks resolve actions such as vslx.vslx_set_linecards. Done means actions can remain callable from action chains and workflows while being omitted from both user-facing action lists; the issue does not name implementation files or tests.