Before this commit, the `getFirstElementForXpath` function is used in the unit test for the burndown chart. This function is used to select a HTMLELement with xpath expression and could be used outside the unit test of the burndown chart. This commit externalizes this function in a project test utils JS file to use this function in another unit tests file if needed. task-2924268 closes odoo/odoo#97574 Related: odoo/enterprise#30173 Signed-off-by: Laurent Stukkens (ltu) <ltu@odoo.com>