Improve undo history so that every undo corresponds to one user input

[haraldharders]

When working in the Designer, I sometimes have to undo changes. And this experience is quite often very confusing and annoying.

For every change in the workflow, you have to press undo once. However, quite often, one user interaction results in other actions such as automatic move of the donwstream tool, change of size of a tool container etc. In such cases, you have inserted a single tool but need to press undo a couple of times to get back to the original situation. It is, however, often not clear how often. In most cases, I fail using undo at the end and revert my changes by hand.

Please change undo towards undoing one user-action in one undo step.

In case there might be users who like the current behaviour, you might make this a user setting how to deal with the undo history.