Fix various arcade system metadata issues

[shizmob]

• The Triforce is generally considered a SEGA system, even if Namco made some PCBs for it. It has outer SEGA part/chassis numbers, runs SEGA firmware and software, uses SEGAs GD-ROM/DIMM game delivery system, and has SEGA manuals. Aside from some licensing and providing the base GameCube, Nintendo was uninvolved; Dropped as per comments below
• Namco System 357 and System 369 are not disc-based systems and can not accept discs, so they don't really have a place here;
• Namco System 246 and 256 are, for disc purposes, the same system. The Super System 256 does not accept discs;
• The SEGA Nu takes DVDs, not blu-rays;
• Add the SEGA ALLS, which takes DVDs.