Improve linking between groups assigned to entries and JabRef's internal group system
Is your suggestion for improvement related to a problem? Please describe. Renaming or editing groups in the entry editor does not seem to be linked with the rest of JabRef's group system. Apparently, group of an entry that have not been created explicitly in the sidebar, are ignored on the groups sidebar.
Describe the solution you'd like When groups in the entry editor are edited, ask whether to create a group in JabRef if it is not already there (possibly the same for renaming, but that might be harder). Also, maybe check whether there are groups assigned to entries that aren't available in JabRef's internal group system.
Additional context

Refs #7129
There have been 3 pull-requests already that try to implement something similar for "automatic keyword groups", but apparently it ain't easy.
- the
{} biblatex sourcetab is also not linked.- Changing data within the groups field will add to existing groups, but will not create new groups.
- Adding the linkage would probably allow to import groups :)
To ponder about: If such a linkage is implemented, the import of entries with data in groups field will automatically create new groups in my library, even though new groups may not necessarily be wanted. How to find these new groups in a large database with 5000+x entries and hundreds of groups? Assign special colour to them? Mark them as being automatically created? Have some kind of warning / popup / or dialogue that allows user to decide upon import? If so, what if the entries had just been copy / pasted? What if I want to export my library but export without groups? ... etc.
Yes, probably not trivial.
I understand the current concept of JabRef (manual) groups is to add them in the JabRef comment-section in the .bib file. Then show entries that have the group assigned to them under the group in the group tree.
Basically, I agree with the aspects you brought up for pondering.
An easy first mitigation might be the consideration of this in the integrity check.
Idea for a issue solution: Maybe a general purpose method could be implemented to update fields in a list of entries by providing a supplier, and the supplier could be different for updating keywords or groups. As this in theory could be an undoable ui action this could be implemented as a SimpleCommand.
check https://github.com/JabRef/jabref/issues/4681