Structuring logs of diagnostic logger

[rauno56]

Implementing #63 got me thinking about our diag logger.

Whenever I see variables in log messages(api.diag.info(`This happened with ${param} for ${type}!`)) I see a lost opportunity to structure the log entry:

1. Thought's on using structured logging everywhere instead? An API similar to pino perhaps:

log(object, string);
log(object | string);

So that the inline example above would look like:

api.diag.info({ param, type }, `This happened!`);
// { "lvl": 30, "time": 1621583582356, "msg": "This happened", "param": "Param value", "type": "Type value" }