[FIX] tests: clean the browser even on failure
[FIX] tests: clean the browser even on failure

When a Chrome headless test fails the browser is not cleaned and could
lead to a mix with other tests when the same method is called.

Also, the multiline assertions gives an unreadable message when the
assertion fails.
Finally, it happens that a thread does not have an 'url' attribute and lead to a crash when the logger tries to show the thread url.

With this commit, the browser is cleaned, even on failure and the
assertions are now one line.

Closes:  #26432
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo