If resized version of full-image requested, attempt to load a cached resized version of it first

[rdiaztushman]

In Assets\Site\Controllers\Asset::read(), if width & height params have been set in the request, we should try feeding a cached version of the image rather than resizing it on the fly. Same process as cachedThumb(), but saving the file in this folder:

$app->get('TEMP') . "assets_resized"