[FIX] point_of_sale: the product name field changed to display_name to include variants information, this should be reflected in searches as well.
[FIX] point_of_sale: the order uid were generated via timestamp, which were not sequencial or easy to understand, they are now generated with the order id and order sequence number which are sequencial
[FIX] point_of_sale: invoicing in the pos printed the wrong order due to a mismatch between order ids and invoice ids
[IMP] models: improve code of _convert_to_write(), make it easier to read
[FIX] product, point_of_sale: add a display_default_code context option that can remove the internal reference (default code) from the displayed product name. Used in the point of sale to unclutter the receipt & GUI
[FIX] mrp_operations: use list instead of record set for o2m

In v7, accessing a o2m returned a list of browse record while it returns a recordset in v8.
The method _move_pass expects a list so a manual conversion is required.
Fixes #1787
[FIX] models: unexpected missing value when checking for a field in cache

At the end of _prefetch_field(), a check is made to ensure that the cache
contains something for the field to prefetch. The check was incorrect because
the cache was checked for a regular value only.
[FIX] models: improve rationale for the management of flag 'recompute' in context

When the context contains 'recompute': False, the recomputation was not even
prepared. Now both create() and write() prepare the recomputation by invoking
method modified(). The flag only controls whether method recompute() is invoked.
In addintion, the former flag 'no_store_function' was converted to the flag
'recompute', so that both create() and write() use the same flag.