Spoolholder for Folgertech FT5 (V2)

A revised version of [this design](https://www.thingiverse.com/thing:1870105)
Added :
- A second level for large 300mm spools
- A number of inserts to fit with the inner spool diameter of ~50mm
- Filament guides that clamp on the 10mm tube/bar.

Base and tubing is still the same as the previous version.