Offer endpoints allowing to undo/redo actions

[elodieburtin]

Undo/redo buttons could be very useful in Cytomine viewer. Since actions are already stored in the database, would it be possible to return in responses of creation/update/delete the ID of the performed action? And to offer endpoints allowing to undo/redo a given action (identified by its ID). It seems to me that it can be limited to actions performed on annotations, but it should be discussed.

The undo/redo mechanism may also be the responsibility of the front-end alone, what do you think is best?