Investigate creating an installer template based on launcher packages

Look into whether it's possible to create an installer template that game owners could drop into a packages folder generated by the packager tool and build an installer from without any additional work.

Ideally it would;

• Pick up the game ID, name and version from the manifest
• Bundle all zip files in the folder and, upon install, extract them to the target folder (reverse of what the packager does)
• Bundle an install of the launcher itself and run it (with noDowngrade flag)
• Register the installed game with the launcher using the manifest
• Check for an existing install of the game and update it in the same directory as it's currently installed to (and update the launcher with the new manifest)