MP-579: convert email to lower case when creates invitation

(cherry picked from commit a5d5565f)

internal/service/service_invitation.go

@@ -3,6 +3,7 @@ package service
 import (
 	"context"
 	"errors"
+	"strings"
 	"time"
 
 	"gitlab.mashroom.com/mashroom/backend/common/api/grpcctx"
@@ -42,7 +43,7 @@ func (srv *serviceImpl) InvitationCreate(
 		HostID:    req.GetHostId(),
 		Invitee: model.User{
 			UserID: req.GetInvitee().GetUserId(),
-			Email:  req.GetInvitee().GetEmail(),
+			Email:  strings.ToLower(req.GetInvitee().GetEmail()),
 			Name:   req.GetInvitee().GetName(),
 			Phone:  req.GetInvitee().GetPhone(),
 		},

internal/service/service_landlord_reference.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"net/http"
+	"strings"
 
 	"gitlab.mashroom.com/mashroom/backend/common/api/grpcerr"
 	"gitlab.mashroom.com/mashroom/backend/common/generic/log"
@@ -67,7 +68,7 @@ func (srv *serviceImpl) LandlordReferenceSave(
 			{
 				Role: notification.Role_ROLE_LANDLORD,
 				Contacts: &notification.Contacts{
-					Email:    req.GetInvitee().GetEmail(),
+					Email:    strings.ToLower(req.GetInvitee().GetEmail()),
 					Phone:    req.GetInvitee().GetPhone(),
 					Fullname: req.GetInvitee().GetName(),
 				},