- Added the support of form payment.
- Fixed payment form's errors not being displayed.
- Fixed a crash when paying on e-commerce with a saved token.
(dev commit, need to clean the code)
The installation of a new acquirer was a bit complicated : from settings,
check the acquirer, then apply (install the module) then list view of
acquirer and finally edit it in form view.
This needed to be simplified. The payment acquirers are pre-filled
in payment. From the kanban view an `Install` button installs and
redirects to the form field.