Add an option in the masonry snippet's allowing to choose among multiple templates for the snippet layout. The usability of the snippet also has been reviewed (restrict the ability to control background on deeper boxes). Also reviewed the bg-200 use on boxes and replaced them with a preset as otherwise it seems buggy to not be able to remove the bg-200 by selecting a preset (other than hitting the trash icon in the colorpicker). Part of https://github.com/odoo/odoo/pull/67361 task-2463033 closes odoo/odoo#67361 Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com> Co-authored-by: smottet <oms@odoo.com> Co-authored-by: qsm-odoo <qsm@odoo.com>