MFNano filter - easier build

After assemblying my MFNano filter I noticed some small things that could be improved, so I took some time and updated the original design with the following changes:

6x3 magnet holders

• 0.05mm deeper
• slightly enlarged the magnet hole to allow dealing with poor manufacturing tolerances
• added hole to allow glue to escape and not act like a spring pushing back on the magnet
• reworked most geometries as the cad had them slightly offset between eachother. This is most probably just an issue with fusion360, but I had to fix them to ease changing the design

plenum body

• enlarged the fan housing by 0.15mm to have an easier time with largers fans (like GDStime)

BOM and assembly guide remains unchanged, so check the original project for guidance