Make the user string in granting operation of project is case insensitive

Currently the user name of login operation is case insensitive. User can login in kylin with lower case string or upper case string. But it is not granting operation.

If we use lower case string of user name in project granting operation, there will be no exception but the user can not set the project.

The reason is that the sid in AccessService/AclService is not case insensitive