Make langtrace compatible with OTEL collector

[dylanzuber-scale3]

This PR updates the core span ingestion route to ingest spans collected from a OTEL collector. Note that this supports only OTLP spans and NOT metrics yet. And this support json on the transport layer.

[codefromthecrypt]

can you add a desc about what this means? I assume it means accept OTLP span (not also metrics) data, on the HTTP transport (not sure json or proto, but I think most are accepting proto)

[karthikscale3]

can you add a desc about what this means? I assume it means accept OTLP span (not also metrics) data, on the HTTP transport (not sure json or proto, but I think most are accepting proto)

can you add a desc about what this means? I assume it means accept OTLP span (not also metrics) data, on the HTTP transport (not sure json or proto, but I think most are accepting proto)

Thank you and apologies for the confusion. Updated the description. This change support OTLP span on json http transport. We plan to support metrics soon and proto is on the near term roadmap for us.