This patch allows dropping material assets from material slot under the mouse
cursor. Before this change the material slot had to be hand-picked from the
properties panel.
For consistency it is chosen to do this in any shading mode as the tooltip shows
what is exactly going to happen during release.
{F10277324}
There seems to be an issue in more complex scenes. Not able to reproduce in master, so need to check.
{F10277318}
The feature also works for other object types than Meshes as it uses the drawn surface on the
GPU to detect the material slots.