The cursor features a "transaction" object to manage application-
specific data in relation with cursor operations. In its initial
implementation, the transaction object was created by the registry.
This created a requirement: in order to be used in environments, a
cursor had to be created by registry.cursor().
We now remove that unnecessary technical requirement by making
environments create the transaction object on demand.
closesodoo/odoo#80644
X-original-commit: e902713648bca329e6821859462b2128aad62c09
Signed-off-by: Raphael Collet (rco) <rco@openerp.com>