elastic-opentelemetry-instrumentation-openai: Add support for tracing embeddings calls

[xrmx]

What does this pull request do?

Add support for tracing openai embeddings sync and async api. Traces will be something like:

    {
        "name": "embeddings all-minilm:33m",
        "context": {
            "trace_id": "0x34b6f145212c169ea39a980ff670dee3",
            "span_id": "0x74b9bd94f2ea6f31",
            "trace_state": "[]"
        },
        "kind": "SpanKind.CLIENT",
        "parent_id": null,
        "start_time": "2024-09-27T14:55:13.104397Z",
        "end_time": "2024-09-27T14:55:13.261547Z",
        "status": {
            "status_code": "UNSET"
        },
        "attributes": {
            "gen_ai.operation.name": "embeddings",
            "gen_ai.request.model": "all-minilm:33m",
            "gen_ai.system": "openai",
            "server.address": "localhost",
            "server.port": 11434,
            "gen_ai.request.encoding_format": "float",
            "gen_ai.response.model": "all-minilm:33m",
            "gen_ai.usage.input_tokens": 9
        },
        "events": [],
        "links": [],
        "resource": {
            "attributes": {
                "telemetry.sdk.language": "python",
                "telemetry.sdk.name": "opentelemetry",
                "telemetry.sdk.version": "1.27.0",
                "telemetry.distro.name": "elastic",
                "telemetry.distro.version": "0.2.0",
                "process.runtime.description": "3.10.12 (main, Sep 11 2024, 15:47:36) [GCC 11.4.0]",
                "process.runtime.name": "cpython",
                "process.runtime.version": "3.10.12",
                "os.type": "linux",
                "os.version": "6.1.0-1034-oem",
                "telemetry.auto.version": "0.48b0",
                "service.name": "unknown_service"
            },
            "schema_url": ""
        }
    }

Related issues