Bug 32030: Modal - Make warnings sticky at the top

Bug 32030: Modal - Make warnings sticky at the top

Warning messages are displayed when a form is not submited because
something is wrong on the form.
We should notify the user on the visible screen, not at the top of the
form that could be hidden.

Signed-off-by: Jonathan Field <jonathan.field@ptfs-europe.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>