Chore: Move ReqContext to contexthandler service (#62102)

* Chore: Move ReqContext to contexthandler service

* Rename package to contextmodel

* Generate ngalert files

* Remove unused imports

pkg/middleware/middleware.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/grafana/grafana/pkg/models"
+	contextmodel "github.com/grafana/grafana/pkg/services/contexthandler/model"
 	"github.com/grafana/grafana/pkg/services/org"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/web"
@@ -21,7 +21,7 @@ var (
 	ReqOrgAdmin            = RoleAuth(org.RoleAdmin)
 )
 
-func HandleNoCacheHeader(ctx *models.ReqContext) {
+func HandleNoCacheHeader(ctx *contextmodel.ReqContext) {
 	ctx.SkipCache = ctx.Req.Header.Get("X-Grafana-NoCache") == "true"
 }