Fixes #5958 - content-view puppet module operations

- puppet modules searchable by name, author and uuid
- authors of content-view puppet modules are searched based on name when they are missing
- updated api docs
- standard error handling for required parameters
Fixes #6397 - cv sys in error msg BZ1111240

Change error message in the authorize_remove_environments action the
ContentViewsController so that it references 'content host' instead
of 'system'.
Merge pull request #4304 from tstrachota/5958_cv_puppet_modules

Fixes #5958 - content-view puppet module operations
Merge pull request #4351 from dustint-rh/content_view_failure_msg_system

Fixes #6397 - cv sys in error msg BZ1111240