The ability to stretch / narrow down the image appears not at the edges of the image

[AleksandrRybalt]

1. Summary: The ability to stretch / narrow down the image appears not at the edges of the image. 2. Description: The ability to stretch / narrow down the image appears not at the edges of the image. 3. Environment: Windows 10 Pro Build 19043.1288 LazPaint 7.1.6 4. Steps to reproduce Choose 'Edit shape'; Move the cursor to the edges of the image, then move it inside the image. 5. Expected result The ability to stretch / narrow down the image appears at the edges of the image. 6. Actual result The ability to stretch / narrow down the image appears not at the edges of the image. 7. Attachment: https://user-images.githubusercontent.com/89531854/139295533-e1c74a66-b1d7-48d3-9fb7-b12c9b8f2937.mp4

[circular17]

This could be improved using a trapezoid hit box.