Node.js agent v12.0.0

Notes

Dropped support for Node.js 16 (#2394) (1870010)
Removed legacy context manager (#2404) (321244c)
Removed support for redis less than version 2.6.0 (#2405) (e2c0a31)
Removed instrumentation for director (#2402) (1b355e7)
Added server.address to amqplib spans (#2406) (09636a4)
Updated mongodb instrumentation to drop support for versions 2 and 3 (#2398) (a0ae32a)
Migrated instrumentation for next into agent (#2409) ([b55d8e1](https://github.com/newr elic/node-newrelic/commit/b55d8e1ca09e6055ea09f4fcd773a05245e7203f))
- You no longer need to load Next.js instrumentation via @newrelic/next.
- Instead you must load the agent via NODE_OPTIONS='-r newrelic' next start

Added test configs for defined targets in the aws test suite (#2403) (cf514d9)
Added producer and consumer metrics to kafkajs instrumentation (#2407) (41c1cc6)
Switched to using Node built-in test runner (#2387) (b9f64b7)
Updated @newrelic/native-metrics to 11.0.0 (#2412) (aef69e2)
Updated dashboard links in developer-setup.md (#2397) (16866da)
Verified MySQL host:port metric is recorded (#2400) (74176f7)

Removed mongodb-esm tests as they are not atomic and conflicting with mongodb tests in CI (#2416) (e587b9d)
Updated minimum version of lesser used versions of 3rd party libraries (#2399) (ef8c006)

We recommend updating to the latest agent version as soon as it's available. If you can't upgrade to the latest version, update your agents to a version no more than 90 days old. Read more about keeping agents up to date. (https://docs.newrelic.com/docs/new-relic-solutions/new-relic-one/install-configure/update-new-relic-agent/)

See the New Relic Node.js agent EOL policy for information about agent releases and support dates. (https://docs.newrelic.com/docs/apm/agents/nodejs-agent/getting-started/nodejs-agent-eol-policy/)