Usability: FilterVariable alias should default to property name

[tlisonbee]

This suggestion would be a very minor improvement but often the alias for a FilterVariable just ends up being the same as the property name so it would be nice if that was used as the default.

E.g.

Dashboard() \
        .with_name(name) \
        .with_charts(*charts) \
        .with_filters(
        DashboardFilters() \
            .with_variables(
            FilterVariable() \
                .with_property("aws_account_id")
                .with_alias("aws_account_id")
                .with_value(aws_account_id))