Suggestion: combine Screen Lineal and Crosshairs for mouse - all activated with double press of Strg

### Description of the new feature / enhancement

I'd wish there'd be a small box giving me the position of my mouse pointer. After one click the box would stay - and indicate the coordinates of the click by having a small black border, but a short red pointer/line to show where the click is measured from.
I could move the lineal freely to ne coordinates and click again - this time a 3d line of texts would indicate the distance in px AND in cm/inch from the first click. A fourth line would show me the area covered by the resulting rectangle in in px, AND in cm^2/inch^2.

On e.g. double click the screen linal as well as the crosshairs would disappear. All the measurements, however, would be transferred to the clipboard.

This would combine the screen lineal and the crosshair in one app. At the same time the lineal shows you the position of your mouse, making double Strg to activate an obvious choice.

This would enhance usability for designers - and anyone who sometimes needs exact measurements.

### Scenario when this would be used?

At the same time the lineal shows you the position of your mouse, making double Strg to activate an obvious choice.

This would enhance usability for designers - and anyone who sometimes needs exact measurements.

### Supporting information

This would combine the screen lineal and the crosshair in one app.

The request describes combining Screen Ruler and Crosshairs, but it names no source files, tests, or entry points. Start by locating those two utilities and their activation and clipboard-handling paths. Done would require an agreed interaction design covering measurement display, double-press activation, dismissal, unit conversion, and clipboard output.

Written by the indexing model from the issue text.