Higher-order measurement button callback function: clears existing highlights/selections,
creates and activates a new measurement state handler for the chosen measurement type,
and updates the UI to reflect that the tool is active.
Parameters
app: Object
The application main context.
state: Function
The State class to instantiate (e.g., PolygonMeasurementState).
button: HTMLElement
The button that was pressed (for UI context/focus).
Higher-order measurement button callback function: clears existing highlights/selections, creates and activates a new measurement state handler for the chosen measurement type, and updates the UI to reflect that the tool is active.