Formatter improvements

[timotheeguerin]

List of things that could be formatted better:

1. Decorator with a single value being very long could be formatted in a single line instead of splitting

@doc("with a very long comment ......")

formats to

@doc(
  "with a very long comment ......"
)

2. Mixes too long line

interface DocumentModels mixes ResourceOperations<ModelSummary, ErrorResponse>, ResourceOperations<ModelSummary, ErrorResponse>, ResourceOperations<ModelSummary, ErrorResponse>, ResourceOperations<ModelSummary, ErrorResponse> {}

Try to format to this?

interface DocumentModels mixes 
    ResourceOperations<ModelSummary, ErrorResponse>, 
    ResourceOperations<ModelSummary, ErrorResponse>, 
    ResourceOperations<ModelSummary, ErrorResponse>, 
    ResourceOperations<ModelSummary, ErrorResponse> {
          
}

3. Interface should keep empty lines between operation

Like namespaces it shouldn't concat all operation together but preserve an empty line if there is 1+ between operation