Stock Picking: group by partner and carrier and scheduled date

This module extends the existing grouping of transfers by partner and carrier so that the scheduled date is also taken into account. On each operation type (for example Delivery Orders) a new checkbox 'Group pickings by date' appears in the form, next to the transfer type field. It is only visible to users with the technical/developer setting enabled.

When this checkbox is ticked and the operation type already groups pickings, Odoo will only put a new move into an existing transfer if that transfer is scheduled on the same day. The day is calculated using the time zone of the warehouse contact, or the company contact, or the current user, falling back to UTC, so the day boundary matches the local working day.

• The grouping is skipped when the operation type does not group pickings, when the related sales order uses the 'as soon as possible' delivery policy (one delivery per order), or when the manual merge context is used.
• The module touches stock.move to add the date condition to the grouping search, and stock.picking.type to store the new option.

No new menus, reports or scheduled jobs are added; the change is a configuration option plus an automatic rule applied when transfers are created from moves.