Ender 3 PSU inner support

This is inner side support for Ender 3 PSU.

Originally, the power cable cover is only supported with outside's 2 screws on plastic parts.

This part can make PSU more strongly.

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Version 1:
For installation, 2 screws on PSU's z-axis side are needed to be removed.
But, more strong.

Version 2:
Installation is more easy but less strong.