Feature summary (what you would like to be able to do and where):
Add EditGroups tools for all Wikibase cloud users.
Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
provide a high-level overview of the edit group;
facilitate on-wiki discussion about the batch by pre-filling a discussion page for it;
let users undo all edits in this batch. This action creates itself a new edit group that attempts to > revert each edit in the group.
Benefits (why should this be implemented?):
Amongst other things it would allow using the edit groups feature of quickstatements as requested in T326307