mfs: unixfs 1.5 touch and chmod error on raw block

[lidel]

Discussed with @gammazero and decided to extract this to separate issue, to unblock testing #653 in Kubo 0.30.0-rc1

After #653 we now have a bug in ipfs files touch and ipfs files chmod. They fail when we execute them against raw blocks.

Repro steps with ipfs/kubo#10478:

$  echo -n "hello path gw" | ipfs add --cid-version 1 -Q  --raw-leaves --to-files /raw-test-1
bafkreiehuhfvxn7w4i5hexlhq4a3y7jf5kfogsvmm5zlfxg5poj4oqozyu

$ ipfs files touch /raw-test-1
Error: expected a ProtoNode as internal node

$ ipfs files chmod 0644 /raw-test-1
Error: expected a ProtoNode as internal node

Hopefully we can add code that detects when node is a raw block and upgrade it to dag-pb before setting mode/time (somewhere around here). We have some prior art for detecting Raw blocks here.

[gammazero]

Fixed by PR #653