Dual Adjustable Spool Holder

Modified spool holder to hold two spools with adjustment on both sides. Added 0.2mm clearance to the wheels ID to avoid post-print rework as the original model had too little clearance there. Rearranged the parts so the movable supports don't fuse to the main structure and added a small support piece to facilitate bridging without needing to add support material in the slicer.