(Suspected) issues in DMN configuration admin

[sergei-maertens]

Business topic: DMN

• Configuring in/output variable mappings and then changing the decision definition to use -> doesn't clear the mapping. The dropdowns can't find the input/output variables and render in "empty" state, but there still is configuration behind the scenes.
• Removing a form variable likely does not remove it from the DMN input/output variable mappings
• A parameter that was removed in the decision definition (in a new version, for example, or renamed) is not cleared (similar to the two cases above)

Some UI controls to show there is still data with a dead reference is probably in order, the user can then decide to remove or update the mapping?

• [ ] Show warning(s) inside DMN configuration modal
• [ ] Show warning icon on logic tab if DMN configuration errors are detected
• [ ] Show warning icon with DMN logic rule/action if errors are detected