[REM] stock: remove dead code of stock move
[REM] stock: remove dead code of stock move

- Remove the unused field call string_availability_info
on the stock.move model. It was used in version 11.0
in a form view, this form views has been merge and
this fields is now unused.
- Remove onchange_quantity function, because the product_qty
can't be change (_set_product_qty doesn't allow that) and
the product_id is required.

closes odoo/odoo#42972

Signed-off-by: Simon Lejeune (sle) <1969d8dff896674c2d819e813f5e88ca826229ab@openerp.com>

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo