Warn user about unsaved changes when leaving the ticket creation page

When leaving a page, for example the ticket creation page, users should be warned about unsaved changes.

Current behaviour: While writing a ticket, a user decides to "show all locations", "show all categories", or anything else that takes him to another page. The user is not notified about unsaved changes, and once they return, the form is blank again.

Expected Behaviour: When the Ticket form is not empty, GLPI should ask if the user wishes to continue and lose any unsubmitted details.