Ender 3 PSU relocation - added support

I loved that @Qieres created this mod. I could not find PSU relocation mod for the old PSU style. Thank you. The only thing that was lack luster IMO was the AC power plug mounting. The 2nd hole was not allowing a screw to properly bite into the plastic to mount it. Plus the mounting position was a little flimsy. So I added a supporting angle piece to the design and made sure there was a proper mounting hole for the screw on the right side.