Allow user to reset personnal view from prefs.
When too many columns are added to the personnal view, this can generate too long SQL request.
Without answer from the server, the user is not able to access the columns personalization form.
So, in the user prefs, add a "reset" button
1/ simple => delete all records in glpi_displaypreferences
2/ by type => add a new tab, with the list of types with a personal view and a massive action to drop them