[feat]: generate code coverage report after tests

[getlarge]

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

I used Node.JS test runner to write integration tests for the instrumentation but were not able to generate code coverage.

Describe the solution you'd like

Maybe using c8 ?

[robertsLando]

Wondering how to do them too here: mqttjs/MQTT.js#1697

[robertsLando]

FYI: node_modules/.bin/nyc --reporter=lcov --reporter=text node -r esbuild-register test/runTests.ts