Prioritize smaller downloads in Applications Manager

Selected applications for download / update to queue based on file size (+ its pre-requisite).

In the settings, set option to prioritize the smaller download / install size.

This is more efficient, in a way that more items will be processed right away. Thus, will not wait for other download queue having a large file size.

ReactOS 0.4.10 running under VirtualBox 5.2.24