* Enhance status endpoint

Add ability to change the status format using the Accept header.
 - Supports application/json and text/plain (default) formats
Move logic of status checking to a class.
Added ability to filter out potentially sensitive information from the status result.
 - The public status endpoint only returns public information.
 - Private information is only returned through the CLI command but could be done from an API endpoint later.
 - Sensitive information includes the names of plugins, versions, etc as they could make it easier for someone to breach a GLPI instance.
Add tests for status checker.
Add CLI command glpi:system:status to get the system status.
 - Accepts the --format parameter with the values json or plain (default) to change the output format.
 - Accepts --private parameter with a true or false (default) value to specify if private data should be returned.

* fixes

Co-authored-by: Cédric Anne <cedric.anne@gmail.com>