Moving app from singular to being created for every request (#9889)

* Moving app from singular to being created for every request.

* Automatic refactor

* Adding license header

* Feedback fixes

services/configservice/configservice.go

@@ -4,6 +4,8 @@
 package configservice
 
 import (
+	"crypto/ecdsa"
+
 	"github.com/mattermost/mattermost-server/model"
 )
 
@@ -12,4 +14,5 @@ type ConfigService interface {
 	Config() *model.Config
 	AddConfigListener(func(old, current *model.Config)) string
 	RemoveConfigListener(string)
+	AsymmetricSigningKey() *ecdsa.PrivateKey
 }