Handle correctly when losing access to a ticket after changing its actors

[marien-probesys]

Problem

An agent may have access to a ticket because they are assigned to it.
If after changing the actors the agent no longer has access to the ticket, they got an error.

Solution

If after changing the actors the agent no longer has access to the ticket, redirect to the list of tickets and display a notification explaining that access has been lost.

Specification

In src/Controller/Tickets/ActorsController.php, before redirecting to the ticket, check if the current user still has access to the ticket:

// with $authorizer being a \App\Security\Authorizer
if ($authorizer->isGranted(`orga:see`, $ticket)) {
    // ...
}

If the condition is false, set a "success" notification and redirect to the list of tickets of the organization:

// Translation: "The actors have been updated, but you no longer have access to the ticket."
$this->addFlash('success', $translator->trans('tickets.actors.edit.no_access'));

return $this->redirectToRoute('organization tickets', [
    'uid' => $organization->getUid(),
]);