Alternative for: "If possible save the last selected node in the proof, to reselect it upon loading."

[wadoon]

Alternative version for #3324 using the settings instead of storing it in the proof.

Using a path encoding of the current node (list of child indexes) and a run-length encoding to keep it small.

Missing: Finding the right spot where the KeYUserProblemFile is available and the proof is loaded. The current place is unsuitable.

[wadoon]

@unp1 I now call getMediator().nonGoalChosen(node) with a valid node, but it is not selected. Where is the other place with the logic that the last node should be taken?

[wadoon]

@unp1 @mattulbrich I updated this to the latest main. The current obstacle is the lack of communication bandwidth, which prevents the provision of additional information to the UI world.

I can vaguely remember that we had a conclusion in Feb'2024 that the additional (KeY-/tool-maintained) information should be separated from \settings {}. Correct?