Form Module Improvements - Improve builder flow when wrong field is chosen

Problem: Deleting a mistaken field redirects to root; changing type not possible.

Actionable:

• Remove redirect; stay on same form and scroll position after delete.

• Add “Change Field Type” with compatibility checks and warnings.

• Add “Undo” snackbar for accidental delete.

Success criteria:

• Workflow remains in-context; switching types preserves label/help and compatible settings.

Context: This proposal is part of the broader storyline AM-I-856.