LDEV-5397 Migrate old Bootstrap3 class names into Bootstrap5 in *all* tools' learning * Did this following 2 guides: https://getbootstrap.com/docs/4.1/migration/ https://getbootstrap.com/docs/5.2/migration/ * Apart from changing class names, also performed other updates required in aforementioned guides. For instance, checkboxes, radios, selects have now proper Bootstrap5 structure; removed "media" objects. * Replaced some outdated LAMS class names