Bambu Lab X1 spacer for spool holder - improved for perfect fit

This is a remix of the Spacer made by @Coat.

It's version for M3x30mm screws.

Bambu spool holder has some ledge which prevents it to fit perfectly to the spacer.

I added:

• space for ledge
• a slightly larger screw hole to make it easier to mount
• increased size on 2% because it was small for me (I printed in PETG)
• added foot to decrease pressure

This holder supports usage of holder native way and upside down if you're going to use well-known Spool roller from @thrutheframe (https://www.printables.com/model/278580-bambu-lab-spool-roller).