Move code related to redirection in its own class method. This way all
controllers perform their own actions and checks before calling the
redirection itself. Moreover it is necessary for some controllers to be
able to call the redirection independently outside of the mail/view
controller scope.
This commit also fixes some links generated for mail notification email
buttons. Assign and (un)follow buttons now effectively use the link helper
when generating the associated URL instead of manually crafting it.
Custom routes for notification buttons used in HR and CRM are added.
Indeed in order to be able to fine-tune the behavior called by those
buttons, using dedicated controllers is simpler than trying to use
a generic one. As there are few custom buttons in notification emails
using dedicated controllers does not lead to a code overhead.
xmo-odoo