feat(collector/receiver): expose service.instance.id

[adamantal]

Description

The service.instance.id identifier is unique to a component (a Lambda execution), and it may have several advantages exposing this information:

• due to its manageable cardinality, it is a better candidate for indexing (as opposed to Lambda execution ids, that can be of much bigger magnitude)
• debugging caching issues across consecutive Lambda invocation on the same instance, as the opentelemetry-lambda's collector is persisted across executions

Testing

Tested live on a Lambda function, on top of #2011: