nodejs: allow specifying `application` as part of the `wrap` operation

[jakebiesinger-storyhealth]

Currently all of the NodeJS sqlcommenter packages restrict the allowed comment entries to the DB driver, trace info, and the http route being served. I also want to specify the entry application so that I can tell where the query is coming from (especially in contexts that aren't serving http traffic!)

Are the allowed keys are being restricted on purpose? If so, would you accept a PR that allowed a static value for application to be specified at initialization time?