Feature Request: Approval Workflow for Closing Action Plans

Description:
Currently, action plans within the system can be closed directly by the person to act, without any intermediate approval step from the team lead. For quality assurance and risk mitigation, we would like to introduce an optional approval workflow.

Requested Enhancement:
Enable a configuration option that requires team lead approval before an action plan can be closed. This approval step should apply at minimum to action plans with severity levels High and Critical.
If possible, we would also welcome the option to enable this approval flow for action plans of any severity level.