node.js: Do not enable non-generic instrumentations by default

[wpessers]

Currently the node.js instrumentation layer has a lot of default instrumentations. These default instrumentations are all being initialized when the OTEL_NODE_ENABLED_INSTRUMENTATIONS environment variable is not set. Meaning the wrapper will take longer to initialize due to a bunch of instrumentations being activated that most users probably don't even need.

An example: express, fastify, hapi and express instrumentations are all initialized by default. This does not make sense to me. Usually if people are using these sorts of frameworks they will stick to one. I also don't think we should be making the node instrumentation layer opinionated and that's why I would propose to remove all non-generic instrumentations from the defaults.