Small storage system with slide locks

This is a complete remodel of [Small storage system](https://www.thingiverse.com/thing:1493275) by CaptainObvious. I loved the original screw boxes, but I'm always paranoid handling them, as the catch doesn't keep it closed very tight. So this version includes a slide-lock to keep the box securely closed.

The slide-locks in this design are basically a pair of dovetail joints. The tapered slides keep the slide from falling off even with the lid open. They can come free, but they are simple to re-attach.

See the original thing posting for the bins, which are fully compatible with this version of the box. Though I also remodelled the bins in my OnShape documents, it didn't seem necessary to post them as I made no changes to the design.

As with the original, the box sizes are a grid system based on 38mm sections. I've uploaded most of the compatible box sizes that were included in the original. In this version, the width can only go down to a width of 3 units for the front/back, a