WIP feat: human option bitswap stat

[PedroMiguelSS]

This PR adds human argument to api/v0/bitswap/stat that will be able to print sizes in human readable format (e.g., 1K 234M 2G)

E.g.:

curl "http://localhost:5001/api/v0/bitswap/stat?human=true"

⚠️It needs the following PR merged and released before this one can be:

• test: add human option test bitswap stat interface-js-ipfs-core#559

[PedroMiguelSS]

This PR will be closed as human option is only implemented on the CLI. See ipfs/js-ipfs#2619.

go-ipfs implements this feature only on the CLI and js-ipfs should implement it on the CLI as well for the sake of consistency.