Improve ConfirmDialog to support multiple closing states

[Cyclone1337]

Problem:

Currently, when the user closes the ConfirmDialog by pressing the X button, the dialog automatically returns false. This conflates the “No” response with “Closed via X”, which can be misleading in some workflows.

Desired behavior:

The ConfirmDialog should differentiate between multiple closing states:

• Confirmed → user clicked Yes

• Canceled → user clicked No

• Closed → user closed the dialog via X

This allows developers to handle each case explicitly.

Possible additional workaround:

Optionally allow the X button to be hidden, forcing only explicit Yes/No responses.

Notes / Suggestions:

• Consider returning an enum instead of a bool to represent the three states.

• Ensure backward compatibility.
  The Delete configuration should still only require a simple true/false return value, as before.
  In contrast, the Yes/No configuration should support all three states, because No and Cancel can represent two different outcomes.

Example:

"Should the unused node types also be removed?"

• No → Do not remove the unused node types, but continue the deletion process.

• Cancel → Abort the deletion entirely.

• Yes → Delete both the nodes and the unused node types.

This ensures that existing Delete workflows continue to work with true/false, while the Yes/No configuration can express the more nuanced states.