Show position or size on Canvas

This MR is a small add on to !753 (merged) . It shows position for Crop , Rectangle ,ellipse and Line tool with ALT modifier.

Test Plan

Add a rectangle , ellipse or line tool with ALT modifier . Also move the crop rectangle. It should display the position or size.

Formalities Checklist

• I confirmed this builds.
• I confirmed Krita ran and the relevant functions work.
• I tested the relevant unit tests and can confirm they are not broken. (If not possible, don't hesitate to ask for help!)
• I made sure my commits build individually and have good descriptions as per KDE guidelines.
• I made sure my code conforms to the standards set in the HACKING file.
• I can confirm the code is licensed and attributed appropriately, and that unattributed code is mine, as per KDE Licensing Policy.