[FIX] account: fix cash bank statement import button

Go on the accounting module, you'll find a kanban view with a few
cards including "Bank" and "Cash". Click on the Cash card.

The default import button doesn't appears because it is hidden.
The reason of this hiding is that the bank statements of type "Bank"
have a custom import method and the users where confuse. They
didn't know which is the right button for the special import so
we hid the default import button for the whole model.

But there is also a "Cash" type bank statement who doesn't have that
special import and his default import button is hidden too.

This commit checks the type of the bank statement and hide the default
import button only if the type is not "Cash".

OPW-2090477

closes odoo/odoo#39827

X-original-commit: ee45228a
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>