[iDVBUG] unwanted behaviour of copied shapes in shape paint mode

[Michaelazzz]

Describe the bug
Copied shapes in the shape paint mode display the unwanted behaviour of mimicking the changes made to the original shape.
This is caused by a shallow copy in the applyMask function in ShapesManager.cs

To Reproduce
Steps to reproduce the behavior:

1. Go to Paint Shape mode
2. Add shape
3. Copy shape
4. Attempt to change the size or position of the shape
5. See error where the changes to one shape occurs across all the copied shapes
   Expected behavior
   Once a shape is copied it must able to manipulated independent of the original or other copied shapes.

[Michaelazzz]

Resolved by PR #448