Add configuration options in the Admin UI for all content set in meta.vm

We need this for example to solve the problem introduced in XWIKI-23160 which caused a very important UX regression (users now enter content in HTTP META without including meta.vm). See for ex https://forum.xwiki.org/t/xwiki-17-10-3-users-and-groups-not-loading-anymore-in-admin-panel/18190

See also the comments at https://forum.xwiki.org/t/move-default-xwikipreference-ui-elements-to-templates/15911/7