Add show action for all modules to print and register attributes if needed

[rmb82]

It's possible to add "show' action to print all raw (or not) attributes of user, group, hbacrule, sudorule, idview ...etc ?
To register attributes needed and reuse them.

as :

• ipa group-show group_name --raw
• ipa user-show user --raw

Thx

[t-woerner]

There is an older draft for the query mode: #782
This needs to be adapted and extended.