Bugfix Paint UI interface stops hotbar scrollwheel

[xNarnia]

This change fixes the following use case:

If I press on the Paint Tool or Eyedropper tool on the Paint Toolbar When I close the schematics window by pressing the X button on the top right Then the scrollwheel will no longer function on the main UI until I re-open the Paint UI

Changelog:

• Add Hide() method call to close of Paint UI window