Adds animated raindrops. Test

Technical Information
This effect needs to be the first effect on the layer if you are working with images or videos (i.e. textures) that are bigger than the "Max. Internal Texture Size". The Internal Texture Size depends on your PB license and is adjustable in the Configuration tab under "Render Engine". The chapter "FX Order" explains how to drag effects in the Device Tree tab to change the order of applied effects.