AlertingNG: POC of evaluator under feature flag. (#27922)

* New feature toggle for enabling alerting NG

* Initial commit

* Modify evaluate alert API request

* Check for unique labels in alert execution result dataframes

* Remove print statement

* Additional minor fixes/comments

* Fix lint issues

* Add API endpoint for evaluating panel queries

* Push missing renaming

* add refId for condition to API

* add refId for condition to API

* switch dashboard based eval to get method

* add from/to params to dashboard based eval

* add from/to params to  eval endpoint

Co-authored-by: kyle <kyle@grafana.com>

pkg/tsdb/models.go

@@ -19,12 +19,12 @@ type TsdbQuery struct {
 }
 
 type Query struct {
-	RefId         string
-	Model         *simplejson.Json
-	DataSource    *models.DataSource
-	MaxDataPoints int64
-	IntervalMs    int64
-	QueryType     string
+	RefId         string             `json:"refID"`
+	Model         *simplejson.Json   `json:"model,omitempty"`
+	DataSource    *models.DataSource `json:"datasource"`
+	MaxDataPoints int64              `json:"maxDataPoints"`
+	IntervalMs    int64              `json:"intervalMs"`
+	QueryType     string             `json:"queryType"`
 }
 
 type Response struct {