*: hr, hr_holidays, im_livechat, website_livechat This commit turns some `link`/`unlink`/`unlinkAll` to `replace`/`clear`. The commands `replace`/`clear` are easier to understand, and also clearly tells what’s the expected resulting value of this field. This change will help turning big and imperative code into smaller declarative code. Task-2834598 closes odoo/odoo#89852 Related: odoo/enterprise#26673 Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>