[MM-13840] Change eMail as a post-verification action (#10253)

* Change eMail as a post-verification action

* Fix broken test

* comment for special behavior, tests

* govet

* Check for already existent eMails when require email verification is turned on before accepting update

app/auto_users.go

@@ -48,7 +48,7 @@ func (a *App) CreateBasicUser(client *model.Client4) *model.AppError {
 		if resp.Error != nil {
 			return resp.Error
 		}
-		store.Must(a.Srv.Store.User().VerifyEmail(ruser.Id))
+		store.Must(a.Srv.Store.User().VerifyEmail(ruser.Id, ruser.Email))
 		store.Must(a.Srv.Store.Team().SaveMember(&model.TeamMember{TeamId: basicteam.Id, UserId: ruser.Id}, *a.Config().TeamSettings.MaxUsersPerTeam))
 	}
 	return nil
@@ -83,7 +83,7 @@ func (cfg *AutoUserCreator) createRandomUser() (*model.User, bool) {
 	}
 
 	// We need to cheat to verify the user's email
-	store.Must(cfg.app.Srv.Store.User().VerifyEmail(ruser.Id))
+	store.Must(cfg.app.Srv.Store.User().VerifyEmail(ruser.Id, ruser.Email))
 
 	return ruser, true
 }