Move middleware context handler logic to service (#29605)

* middleware: Move context handler to own service

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Co-authored-by: Emil Tullsted <sakjur@users.noreply.github.com>
Co-authored-by: Will Browne <wbrowne@users.noreply.github.com>

pkg/models/user_auth.go

@@ -3,6 +3,7 @@ package models
 import (
 	"time"
 
+	"github.com/grafana/grafana/pkg/setting"
 	"golang.org/x/oauth2"
 )
 
@@ -84,6 +85,7 @@ type LoginUserQuery struct {
 	User       *User
 	IpAddress  string
 	AuthModule string
+	Cfg        *setting.Cfg
 }
 
 type GetUserByAuthInfoQuery struct {