Network support for asset resources

QtQuick3D Network Transparency

This is related in principle to QTBUG-17413, though relates predominantly to images. For example image files containing textures or shader programs. These files must then be made available to the QtQuick3D application for rendering before the model can be completely shown.

Users should be able to

(a) Specify textures for object using URLs (for example, a flickr 3D application). These textures are automatically downloaded from their network-location and used as per a local (file based) texture image.

(b) Load asset files which use URLs for their texture images.