fsds.nim

[Bulat-Ziganshin]

1. don't use templates when proc will be fine, and especially don't export templates
2. I suggest using base16 encoding for keys, since Windows doesn't distinguish 'a' from 'A' and prohibits a few plain string filenames like "CON"
3. path can't contain empty components so ns.field == ns.value == "" should translate into a special value
4. we may need to deal specifically with empty key (ley.len==0)
5. it seems that keys "a:b" and "a/b" are both translated into the same filepath. with base16 encoding, we can replace ":" f.e. with "_"
6. delete shouldn't return failure if file don't exist - according to policy in https://github.com/status-im/nim-codex/wiki/Blockstores