Simplify filestore

[rgrp]

Definitely do:

• Remove pairtree (and OFS) and do something very simple - make sure that filestore with local FS is very simple

Options:

1. Local file only. Allow for uploaders to GS / S3 in the background
   • Advantages: simpler, if local upload can do progress bars etc etc
   • Disadvantages: strain for web-app (upload a 2GB file what happens)
     • This is probably fixable ...
2. Stick with how we are

### New layout without pairtree

Each uploaded file is located on disk at:

{uuid}/{filename}

Alternative:

yyyy/mm/dd/{uuid}/{filename}

Need the uuid to avoid collisions.

Metadata: Store no metadata.