OpenTelemetry support

[Syndesi]

OpenTelemetry might allow to further increase interoperability between Ember Nexus API and existing log and metric collection systems. Although while OpenTelemetry is great for inter-machine-communication, it is quite verbose and might hinder manual log inspection by humans. Therefore OpenTelemetry should not be enabled by default.

Open tasks:

• Research OpenTelementry
  • https://opentelemetry.io/
  • https://opentelemetry.io/docs/languages/php/getting-started/
  • Can OpenTelemetry be consumed via console / stderr only? Or is some sort of HTTP push/pull mechanism required? If the later is the case, then the added complexity might not be worth it.
• Add config option to switch between default logging mode (the currently existing solution, human friendly) and openTelemetry logging mode.
• Add tests to verify that the OpenTelemetry integration is working and is consumable.