`ipfs stats bw` doesn't support --enc json

[MichaelMure]

Version information:

go-ipfs 0.4.17 and git master

Type:

Bug

Description:

All commands should support the --enc options. It doesn't work for ipfs stats bw I suppose because the result of the command is formatted in a PostRun instead of an Encoders.

[overbool]

@MichaelMure ipfs stats bw has a option --poll that supports uninterrupted output. Therefore, I think it's not easy to achieve this feature by using Encoders instead of PostRun.

[Stebalien]

This looks fixable, it's just a bit tricky. The encoder will be called once per item.

[kevina]

How important is this. Maybe this is something we should wait on until we fix the need for using PostRun in most cases otherwise we run into the same problems we had with ipfs ls --stream in particular it appears a header is outputted is some cases.

[Stebalien]

IMO, low priority. Most clients will just use HTTP directly.