Experiment: Register instrumentation with SPI.

[ChrisLightfootWild]

⚠️ 🚧 Experimental 👷

Just toying around with the SPI package as an alternative way to register auto-instrumentation.

Though it uses the InstrumentationInterface as a proof-of-concept, I think we should possibly create a more purposeful interface that fits our needs a little better. eg. the get***Provider()s can be resolved lazily later.

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References:

• https://getcomposer.org/doc/04-schema.md#files

  • autoload file inclusion order is impacted by dependencies
  • if an auto-instrumentation package has the SDK as an explicit dependency, then SdkAutoloader would run first via _autoload.

• https://getcomposer.org/doc/articles/plugins.md#plugin-optional

  • can affect service loading based on above