[FIX] mail: fix inbox mark as read on single message

Clicking on mark as read on a given message would move all messages in
inbox to history instead of only selected message(s). This commit fix
that behaviour so that only the selected message(s) move(s) to history.

task-2284543

closes odoo/odoo#54688

X-original-commit: 3304b89fc799b979b028aa4c7efe902b2f5276c1
Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>