[IMP] gamification_sale_crm: change date filed for definition "Logged Calls"

The field date_close is only computed when writing the state done. In v8, the phonecalls are always created in state done if the user is not in the group crm.group_scheduled_calls (displays menus to schedule calls.
As the field date_closed is then almost never set, change the date field by the one displayed in the form view. opw 614893
fix exception message in report seachr

when we get to the raise statement, `r` is `None`, so displaying it in the
exception message is useless. `name` is what we want to show.
Merge pull request #2796 from gurneyalex/8.0-improve_report_not_found_exception

[FIX] lookup_report: exception message when the report is not found
[FIX] fields: copy origin to avoid sharing field objects between registries

Fix a bug introduced in revision f229974, where shared columns objects are
systematically reintroduced in registries.
[FIX] fleet: contract onchange: ensure dict before executing `get`
[FIX] sale_margin: stored field functions cannot trigger other stored field functions

the update of sale.order margin field was trigger with the margin stored field of sale.order.line: This cannot work with the old api
[FIX] website*sale: product_id_change qty is 0 by default

Thus, need to pass the actual quantity to product_id_change in order to set values correctly
[IMP] fields: split the default value from the compute function

This separation allows to set a default value on a related field, for instance.