[Feature]: SpanProcessor API seems to be limiting

[purkhusid]

Related Problems?

No response

Describe the solution you'd like:

I'm trying to create a SpanProcessor that is very similar to this one here in Java: https://github.com/microsoft/ApplicationInsights-Java/blob/main/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/init/InheritedAttributesSpanProcessor.java

The processor reads the attributes of the parent span and adds it to the child span if it's in the list of approved attributes.

In Java they can easily get the full Span with it's attributes from the Context but this does not seem to be possible in the Rust OTEL implementation

Considered Alternatives

I also considered solving this by using a lookup table so that I could look up the parent span from the span ID that is in the parent context but that is very hard to do(Impossible?) in Rust since the lookup table would outlive the span.

Additional Context

No response