4.2.0 release: Update to use latest Castle Game Engine 7.0-alpha.2 fixes and optimizations

Following the Castle Game Engine 7.0-alpha.2 release, we release a new version of view3dscene to incorporate latest CGE improvements. The relevant improvements include:

• glTF improvements: step interpolation, cameras fix, normal scale handling, ability to pick a subset of glTF
• Integration with Vampyre Imaging Library to read more image formats
• Better key shortcuts in view3dscene to switch views, consistent with CGE editor and Blender