[FIX] pos_six: missing "Send balance" button

To reproduce (16.1 and >):
 1. Install PoS and enable Six payment method
 2. Create a payment method using Six
 (the IP can be set randomly, it does not matter here to have the
 terminal connected)
 3. Add the Six payment method to the PoS configuration
 4. Open the PoS session
-> The "Send balance" button of the navbar is totally missing

For now, the manifest try to load the assets at:
`pos_six/static/src/app/**/*`
But, since 16.1 the file location for the XML and JS is misplaced in
`/static/app` instead of `/static/src/app`,
as such, the template file is missing.

opw-3422166

closes odoo/odoo#128813

X-original-commit: 859390a42cb8b2b10b017dca2ea5734cd8915c49
Signed-off-by: Quentin Lejeune (qle) <qle@odoo.com>
Signed-off-by: Loan Sens (lse) <lse@odoo.com>

addons/pos_six/static/src/app/navbar.js

@@ -1,7 +1,7 @@
 /** @odoo-module */
 
 import { Navbar } from "@point_of_sale/app/navbar/navbar";
-import { BalanceButton } from "@pos_hr/js/BalanceButton";
+import { BalanceButton } from "@pos_six/js/BalanceButton";
 import { patch } from "@web/core/utils/patch";
 
 patch(Navbar, "pos_six.Navbar", {