SSE: Dataplane Compliance (#65927)

Takes a specific code path for data that identifies itself as dataplane instead of "guessing" what the data is.

The data must identify itself by being in the dataplane by having both the following frame metadata properties:

- TypeVersion property that is greater than 0.0
- 'Type' property

The flag is disableSSEDataplane and disables this functionality and uses the old code for all queries regardless.

See https://github.com/grafana/grafana-plugin-sdk-go/blob/main/data/contract_docs/contract.md for dataplane details.

pkg/expr/nodes.go

@@ -14,6 +14,7 @@ import (
 	"github.com/grafana/grafana/pkg/expr/mathexp"
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/services/datasources"
+	"github.com/grafana/grafana/pkg/services/featuremgmt"
 	"github.com/grafana/grafana/pkg/services/pluginsintegration/adapters"
 )
 
@@ -258,6 +259,11 @@ func (dn *DSNode) Execute(ctx context.Context, now time.Time, _ mathexp.Vars, s
 		return mathexp.Results{}, QueryError{RefID: dn.refID, Err: response.Error}
 	}
 
+	if dt, use, _ := shouldUseDataplane(response.Frames, logger, s.features.IsEnabled(featuremgmt.FlagDisableSSEDataplane)); use {
+		logger.Debug("Handling SSE data source query through dataplane", "datatype", dt)
+		return handleDataplaneFrames(dt.Kind(), response.Frames)
+	}
+
 	dataSource := dn.datasource.Type
 	if isAllFrameVectors(dataSource, response.Frames) { // Prometheus Specific Handling
 		vals, err = framesToNumbers(response.Frames)