[DF-4244] set shadow color as a global material property in the game scene
[DF-4244] remove ShadowColor key after import to global material
Merge branch 'origin/development'

Conflicts:
	Sources/Internal/Scene3D/Scene.cpp
[DF-4244] change default shadow blend mode to MULTIPLY
Merge branch 'origin/development'

Conflicts:
	Sources/Internal/Scene3D/Scene.cpp
Merge branch 'origin/DF_4244_shadow_color'