[FIX] mrp: Fix quantity filtering for kits

Purpose
=======

On product list we can see that kits are listed with quantity on hand
equals to the lesser quantity of the kit's components.

When applying the filter **Quantity on hand greater than 0**, the kit
disappears from the list.

The issue is that we compute product quantity from stock.quant, for kits
we don't create a quant beacause it's not a physical product.

Specification
=============
To solve the issue, we extend the method **_search_qty_available_new** from
**stock.product** in **mrp.product**, where we fetch all kits and add the id
of the products that verify the given condition.

opw-2717594

closes odoo/odoo#86262

X-original-commit: 9db235a0d8cb1f7a371a1dec8a441329de5d5eb8
Signed-off-by: William Henrotin (whe) <whe@odoo.com>
Signed-off-by: abla001 <abla@odoo.com>