LDEV-5419 Allow removing org grouping from apply grouping screenTeachers using integrations do not have an obvious access to org grouping management screen. They just see apply grouping to lesson screen. It is good that they can not only create an org grouping, but also remove it there.
LDEV-5083 Make answered questions chart tooltip always visibleWhen there are many students in a lesson, but only one left in a given bar of answered questions, they can not be hovered on to find out their name. In that case the cart switches to non-intersect mode, i.e. the tooltip is displayed even above the bar.
LDEV-5260 Synchronise Flux creationWith high load there could have been multiple Fluxes with the same name and key instead of a singleton for all subscribers to this Flux.