feat: draft - PG semantic convention stability migration

[hannahramadan]

This PR is intended to assist in the transition from the old to new database semantic conventions. Per the database semantic convention stability migration spec, users should be able to set the environment variable OTEL_SEMCONV_STABILITY_OPT_IN to:

• database to emit stable conventions only
• database/dup to emit both old and the stable conventions
• a blank env var will emit old conventions only

The agent is required to maintain this bridge for 6 months and may drop the environment variable in the next major version and emit only the stable database and networking conventions.

This approach was approved for HTTP migration in #1547

Changes:

• db.system -> db.system.name
• net.peer.name -> server.address
• net.peer.port -> server.port
• db.name -> db.namespace
• db.statement -> db.query.text
• db.operation → db.operation.name change

Removed:

• db.user
• net.peer.ip
• net.transport
• net.sock.family
• db.collection.name (Removed because accord to spec, we should only add if readily available)
• peer.service

Added:

• error.type
• server.port

[toncid]

I know that it is out of scope of this PR, but would you be willing to also document the obfuscation_limit: 2000 parameter in this file, please?

The description would be something like:

When enabled by db_statement, this instrumentation will not obfuscate SQL queries longer than 2000 characters. The default limit can be overridden by setting the obfuscation_limit to another integer value.

[toncid]

The config was released in v0.25.0 (on 2023-05-25), but never documented it seems.

[arielvalentin]

It's going to be a while before this is ready for review and merged.

@toncid would you be amenable to submitting a PR that documents the option?

[toncid]

Sure, no problem. Thanks for the quick answer.

[toncid]

@arielvalentin Done - #2122. 🚀