Upgrade to node 14 (#2027)
* Upgrade to node 16
* be more specific with our version and use the new recommended image
* move to 14, once we upgrade parcel, maybe we can go to 16
* fix format number resolved options
14.17 introduced a breaking change where resolvedOptions returns 'decimal' instead of 'percent'. I've logged a bug here:
https://github.com/nodejs/node/issues/39050
