Add integration tests for node database autoinstrumentation

[AbhiPrasad]

We should add integration tests for our node database integrations (mongo, postgres).

This will be nice for us to validate if the auto instrumentation is working as expected (are we generating the db spans as expected). We could also create a matrix with different versions of the auto instrumented libraries.

We could maybe take a similar approach to what is described here: getsentry/sentry-electron#361 (comment)

[AbhiPrasad]

Done with https://github.com/getsentry/sentry-javascript/tree/master/packages/node-integration-tests/suites/tracing/auto-instrument