Files list slow to render when directory contains many files

We're need to paginate the rendering of large directories. We're using react-virtualized for the peers list and the links list in the ipld-explorer, so it'd make sense to use that here.

To deal with really large directories of things, we'd also need to be able to request paginated chunks of a dir listing from the api.

## We did it good if...

- [ ] Files page can render the (first few) files list for a directory containing > 1000 files in < 1s