Generate structured data from object with escape for RFC5424

[nkzawa]

Is your feature request related to a problem? Please describe.
Like the following

 rfc5424.buildMessage('hello', {                              
   structuredData: {                                                         
     "hi@32473": {                                                           
       foo: 1,                                                               
       bar: 2
    }                                                                
  }                                                                   
 });
// [hi@32473 foo="1" bar="2"]

Since you need to be careful about escaping and quote character ("), it'd be nicer if the library can generate it from data.

Describe the solution you'd like

Describe alternatives you've considered

Additional context
vercel#11 We support it in our fork temporarily