[IMP]sale_crm: Add new button (“Sales“) on Opportunity form view.

Add new button (“Sales“) on Opportunity form view and display total amount of related quotes/sales on that stat button.

Task: https://www.odoo.com/web?#id=9370&view_type=form&model=project.task&menu_id=3942&action=327

Pad: https://pad.odoo.com/p/r.fvkticI2jioPxHls
Several typical errors here ...
- you browse the opportunities, but only to use the id field
- you could avoid searching on each id: search on opportunity_id in ids, then browse the sale orders and update the res variable accordingly. This way you will have a method that works in batch and that should be more efficient.