[symfony-auto-instrumentation] Split package into different packages

[joaojacome]

Due to the possibility of using Symfony components on non-Symfony projects, I'd like to propose splitting the current Symfony Auto-instrumentation package into three different packages:

• opentelemetry-auto-symfony-messenger
• opentelemetry-auto-symfony-http-kernel
• opentelemetry-auto-symfony-http-client

The existing opentelemetry-auto-symfony would become a meta-package for the new packages.

This will allow us to selectively enable those instrumentations.

[brettmc]

If the main goal is to be able to enable/disable different parts of the auto-instrumentation, then does it help to know that open-telemetry/opentelemetry-configuration#91 is coming, which will allow fine-grained configuration of auto-instrumentation?
Once we get v1.1 tagged of our core packages, we plan to move auto-instrumentation packages across to supporting this type of configuration. There's an example of how this works: https://github.com/open-telemetry/opentelemetry-php/tree/main/examples/src

[joaojacome]

Looks like that would work too, I'm happy with that :)

Although, I still think the Symfony packages should be split in different packages, as they actually instrument different components.