Add new line to cmdio JSON rendering

[shreyas-goenka]

Changes

This PR adds a new line break to JSON rendering using cmdio. This is useful when we call cmdio.Render multiple times

Tests

Manually

[shreyas-goenka]

Before:

shreyas.goenka@THW32HFW6T bricks % cli fs ls dbfs:/user/hive --output=json
[
  {
    "name":"warehouse",
    "is_directory":true,
    "size":0,
    "last_modified":"2023-06-05T11:49:22+02:00"
  }
]%

After:

shreyas.goenka@THW32HFW6T bricks % cli fs ls dbfs:/user/hive --output=json
[
  {
    "name":"warehouse",
    "is_directory":true,
    "size":0,
    "last_modified":"2023-06-05T11:49:22+02:00"
  }
]

Note the absence of % in the last line of the output, which indicates a new line character in iterm2

[pietern]

Please stick to \n only. On Windows folks seem to get by with \n alone as well.

[shreyas-goenka]

That seems to be the case when using \n with println. I am not so sure about io writer though. We do the same for sync progress events:

cli/cmd/sync/output.go

Line 49 in be10ff9

bw.WriteString("\r\n")

Maybe it's worthwhile testing it out on windows?

[nfx]

yep, please check it on windows

[pietern]

fmt.Println goes through an io.Writer, the two operate at different levels.

Please file a follow up to check out if \n alone is good enough. Use of \r\n on Unix systems could be problematic so I prefer using \n everywhere. If it's good enough for the Go stdlib it is good enough for us.

[shreyas-goenka]

Followup filed at #451