This commits aims to improve the search feature in the export dialog.
Now, the search isn't resetted when a field is added to the export list
anymore. It is also possible to search in the list of fields using the
technical name of the field.
A test has been added for the search feature in debug mode, and another
one has been adapted to verify that the search input still contains the
string previously entered.
task-3266632
closesodoo/odoo#118767
X-original-commit: 83e58a0e7e1a6f50ad03a098829946d56393d496
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>