Batch tree deletion actions when deleting a group

[daniel-wer]

I batched the group-with-subtree deletion, mulitple tree deletion and multiple tree move user actions. The confirm group/tree/node-with-id-1 deletion code is pretty messy and should be consolidated, but I'll probably not do that as part of this PR. My changes should not make it much worse.
I also found a (minor) bug in the undo functionality where when only a single action was triggered, for example, SET_TREE_GROUP, and that was then undone, the save_saga would take the UNDO action and diff the tracing state, although the "undone" tracing state was not set in the store yet. We didn't notice this before, because usually there's a couple more flycam actions or so that follow, which trigger the differ again. To fix this, I changed the save_saga code to take the SET_TRACING action instead which is what undo/redo dispatch to set the new tracing state.

URL of deployed dev instance (used for testing):

• https://___.webknossos.xyz

Steps to test:

• Create a skeletontracing with nested groups and trees. Delete a group that contains multiple trees. Use undo to restore the previous state. The deletion of trees within one group should be "atomic" and be restored with one undo action.
• Select multiple trees and delete/move them. Undo the change which should be "atomic".
• Create a task and check whether the "Are you sure you want to delete the tree with id 1"-warning is still properly shown.

Issues:

• contributes to Make sure atomic user interactions result in "atomic" update actions #4281

---

• Updated changelog
• Ready for review

Outdated, but for reference:

I gave the redux-batched-actions lib a try and the easy case seems to work pretty well (batching multiple actions of the same type). However, group/tree/node deletion is rather complex in our code, triggering Modals with async responses, so using the batched actions in that scenario is not straight-forward. This is why in the current iteration only the DELETE_TREE actions deleting the trees of one group at a time are batched together.
Another problem would be if we wanted to batch actions of different types as redux-saga's take... methods then no longer work out of the box, because they don't know about batched actions. It would be possible to overwrite those take functions to unpack and match the batched actions but that would be rather involved I think.
I've read quite a bit in the issues sections of the library, but couldn't find a good solution yet.

Let's discuss this tomorrow in person :)

[daniel-wer]

Fix for a React warning that I encountered a lot. React complained about the custom prop groupId that was not removed before adding the element to the DOM.

[daniel-wer]

@philippotto I implemented this as discussed and updated the PR description. Should be ready for review :)

[philippotto]

Awesome! The changes look very good and testing went well, too. One thing which I noticed is that the merger mode uses api.utils.registerOverwrite("DELETE_TREE" ...) and that this should probably be adapted to the new batched action. Shouldn't be much work, I assume? Otherwise, deleting multiple trees will probably break the merger mode.

[daniel-wer]

One thing which I noticed is that the merger mode uses api.utils.registerOverwrite("DELETE_TREE" ...) and that this should probably be adapted to the new batched action.

Very good call, I pushed a fix :)

[philippotto]

Awesome, looks good 👍