[REM] stock: remove Forecasted Inventory view

The Forecasted Inventory view has become obsolete, therefore we delete
the code associated with this view. Note that the Forecasted Report
still uses the graph view of this view so we leave it. Because the
Forecasted Report still uses this view + stock.warehouse.orderpoint
relies on the report.stock.quantity model, we leave the model as is.

"forecast inventory" part of b2b task: 2882539
ENT PR: odoo/enterprise#29974
Upgrade PR: odoo/upgrade#3819

Part-of: odoo/odoo#97109