Make alerting notifcations sync (#6158)

* tech(routines): move the async logic from notification to alerting notifier

* tech(notification): reduce code dupe

* fix(notification): dont touch the response unless its an error

* feat(alerting): make alerting exeuction async but flow sync

* tech(alerting): remove commented code

* tech(alerting): remove unused code

* tech(alerting): fix typo

* tech(alerting): implement Context on EvalContext

* tech(alerting): wait for all alerts to return

* feat(alerting): dont allow alert responses to cancel

* Revert "feat(alerting): dont allow alert responses to cancel"

This reverts commit 324b006c96.

* feat(alerting): give alerts some time to finish before closing down

pkg/tsdb/batch.go

@@ -1,6 +1,9 @@
 package tsdb
 
-import "errors"
+import (
+	"context"
+	"errors"
+)
 
 type Batch struct {
 	DataSourceId int64
@@ -20,7 +23,7 @@ func newBatch(dsId int64, queries QuerySlice) *Batch {
 	}
 }
 
-func (bg *Batch) process(context *QueryContext) {
+func (bg *Batch) process(ctx context.Context, queryContext *QueryContext) {
 	executor := getExecutorFor(bg.Queries[0].DataSource)
 
 	if executor == nil {
@@ -32,13 +35,13 @@ func (bg *Batch) process(context *QueryContext) {
 		for _, query := range bg.Queries {
 			result.QueryResults[query.RefId] = &QueryResult{Error: result.Error}
 		}
-		context.ResultsChan <- result
+		queryContext.ResultsChan <- result
 		return
 	}
 
-	res := executor.Execute(bg.Queries, context)
+	res := executor.Execute(ctx, bg.Queries, queryContext)
 	bg.Done = true
-	context.ResultsChan <- res
+	queryContext.ResultsChan <- res
 }
 
 func (bg *Batch) addQuery(query *Query) {