[FIX] web: chain close action on wizard confirm

If a wizard has several steps, or laucnh a second wizard, the view from where has been loaded the initial wizard is finally reloaded
[FIX] account_payment: lin2bank correct fallback condition
[IMP] web: extra comments to explain commit 57b4860

Added some cryptic comments so we remember a bit
why we have a complicated dance with on_close.
Basically we do not want to reload the
original form view until the last popup is closed,
in the case where several wizard (steps) are opened
one after the other.