[servicegraphprocessor] Edge loss attributes from client-side or server-side

[Frapschen]

Describe the issue you're reporting

Edge attributes are set by p.upsertDimensions() whatever span.kind is client or server:

opentelemetry-collector-contrib/processor/servicegraphprocessor/processor.go

Lines 198 to 231 in 304196f

	case ptrace.SpanKindClient:
	traceID := span.TraceID()
	key := buildEdgeKey(traceID.HexString(), span.SpanID().HexString())
	isNew, err = p.store.UpsertEdge(key, func(e *store.Edge) {
	e.TraceID = traceID
	e.ConnectionType = connectionType
	e.ClientService = serviceName
	e.ClientLatencySec = float64(span.EndTimestamp()-span.StartTimestamp()) / float64(time.Millisecond.Nanoseconds())
	e.Failed = e.Failed || span.Status().Code() == ptrace.StatusCodeError
	p.upsertDimensions(e.Dimensions, rAttributes, span.Attributes())
	// A database request will only have one span, we don't wait for the server
	// span but just copy details from the client span
	if dbName, ok := findAttributeValue(semconv.AttributeDBName, rAttributes, span.Attributes()); ok {
	e.ConnectionType = store.Database
	e.ServerService = dbName
	e.ServerLatencySec = float64(span.EndTimestamp()-span.StartTimestamp()) / float64(time.Millisecond.Nanoseconds())
	}
	})
	case ptrace.SpanKindConsumer:
	// override connection type and continue processing as span kind server
	connectionType = store.MessagingSystem
	fallthrough
	case ptrace.SpanKindServer:
	traceID := span.TraceID()
	key := buildEdgeKey(traceID.HexString(), span.ParentSpanID().HexString())
	isNew, err = p.store.UpsertEdge(key, func(e *store.Edge) {
	e.TraceID = traceID
	e.ConnectionType = connectionType
	e.ServerService = serviceName
	e.ServerLatencySec = float64(span.EndTimestamp()-span.StartTimestamp()) / float64(time.Millisecond.Nanoseconds())
	e.Failed = e.Failed || span.Status().Code() == ptrace.StatusCodeError
	p.upsertDimensions(e.Dimensions, rAttributes, span.Attributes())
	})

it does't handle a sense that the two spans have a attribute with same name but different value, like client span have attribute of cluster: A but server span have attribute of cluster: B

we can add prefix to distinguish them:
client_cluster: A
server_cluster: B

[JaredTan95]

make sense.

[github-actions]

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