Adapt calendar highlight option (that "highlight" event linked to the
record we come from) to current JS framework data structures.
note: this changeset also fixes the original `_compute_is_highlighted`
that was would trigger CacheMiss errors, and also adds back the CSS for
highlighting that was lost between 12.0 and 13.0 version.
opw-2131494
closes#40791closesodoo/odoo#41077
X-original-commit: da56e3e7036ecdb3905f4152778e853e080e0163
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>