UserStore migration (#15563)

* Migration completed

* Fix tests

* Fix tests

* Fix tests

* Suggestions

* Trigger CI

* Suggestions

* Merge with master

* Trigger CI

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>
Co-authored-by: Agniva De Sarker <agnivade@yahoo.co.in>

app/webhook.go

@@ -676,7 +676,7 @@ func (a *App) HandleIncomingWebhook(hookId string, req *model.IncomingWebhookReq
 	uchan := make(chan store.StoreResult, 1)
 	go func() {
 		user, err := a.Srv().Store.User().Get(hook.UserId)
-		uchan <- store.StoreResult{Data: user, Err: err}
+		uchan <- store.StoreResult{Data: user, NErr: err}
 		close(uchan)
 	}()
 
@@ -700,7 +700,7 @@ func (a *App) HandleIncomingWebhook(hookId string, req *model.IncomingWebhookReq
 	if len(channelName) != 0 {
 		if channelName[0] == '@' {
 			if result, err := a.Srv().Store.User().GetByUsername(channelName[1:]); err != nil {
-				return model.NewAppError("HandleIncomingWebhook", "web.incoming_webhook.user.app_error", nil, "err="+err.Message, http.StatusBadRequest)
+				return model.NewAppError("HandleIncomingWebhook", "web.incoming_webhook.user.app_error", nil, err.Error(), http.StatusBadRequest)
 			} else {
 				if ch, err := a.GetOrCreateDirectChannel(hook.UserId, result.Id); err != nil {
 					return err
@@ -757,8 +757,8 @@ func (a *App) HandleIncomingWebhook(hookId string, req *model.IncomingWebhookReq
 	}
 
 	var user *model.User
-	if result := <-uchan; result.Err != nil {
-		return model.NewAppError("HandleIncomingWebhook", "web.incoming_webhook.user.app_error", nil, "err="+result.Err.Message, http.StatusForbidden)
+	if result := <-uchan; result.NErr != nil {
+		return model.NewAppError("HandleIncomingWebhook", "web.incoming_webhook.user.app_error", nil, result.NErr.Error(), http.StatusForbidden)
 	} else {
 		user = result.Data.(*model.User)
 	}