Before this commit, when a ListViewHeaderButton was clicked, the view
context wasn't sent to the server.
As ListViewHeaderButton shows, the onClickViewButton API is not correct.
It expects a record in params but this is not correct in the case of
ListViewHeaderButton. So we decided not to pass a record but a getParams
callback that allows us to calculate the params when we need them.
Part-of: odoo/odoo#97558
FrancoisGe
b2a0a1c7d3