`drive.readdir` does not return both entry and prefix

[josephmturner]

If a hyperdrive contains a path corresponding to both an entry (file) and a prefix (subdirectory), drive.readdir only returns the entry (file). https://github.com/RangerMauve/hypercore-fetch/issues/46 and https://github.com/RangerMauve/hypercore-fetch/pull/47 discuss this issue.

Per https://github.com/holepunchto/mirror-drive/issues/14, paths can potentially correspond to both an entry and a prefix. Therefore, when such a duplication exists, should drive.readdir return both values?

[mafintosh]

If easy and no perf cost yea sure. Feel free to poke at that