[Feature] @Attachment provides "attach as pretty-printed JSON" option.

[L-Evg]

If one needs a JSON-ezed attachment it is possible to specify attachment type as:

@Attachment(value = "API Response", type = "application/json", fileExtension = ".json")

However the output will not be pretty-printed so could be hardly-readable for human beings.

Suggestion: @Attachment provides "attach as pretty-printed JSON" option e.g. something like:

@Attachment(value = "Pretty-printed API Response", type = "JSON")