SSE/Alerting: First pass at query/condition translation (#31693)

- Takes the conditions property from the settings column of an alert from alerts table and turns into an ng alerting condition with the queries and classic condition.
- Has temp API rest endpoint that will take the dashboard conditions json, translate it to SEE queries + classic condition, and execute it (only enabled in dev mode).
- Changes expressions to catch query responses with a non-nil error property
- Adds two new states for an NG instance result (NoData, Error) and updates evaluation to match those states
- Changes the AsDataFrame (for frontend) from Bool to string to represent additional states
- Fix bug in condition model to accept first Operator as empty string.
- In ngalert, adds GetQueryDataRequest, which was part of execute and is still called from there. But this allows me to get the Expression request from a condition to make the "pipeline" can be built.
- Update AsDataFrame for evalresult to be row based so it displays a little better for now

pkg/expr/nodes.go

@@ -234,6 +234,10 @@ func (dn *DSNode) Execute(ctx context.Context, vars mathexp.Vars, s *Service) (m
 
 	vals := make([]mathexp.Value, 0)
 	for refID, qr := range resp.Responses {
+		if qr.Error != nil {
+			return mathexp.Results{}, fmt.Errorf("failed to execute query %v: %w", refID, qr.Error)
+		}
+
 		if len(qr.Frames) == 1 {
 			frame := qr.Frames[0]
 			if frame.TimeSeriesSchema().Type == data.TimeSeriesTypeNot && isNumberTable(frame) {