Add more global attributes for selecting parent datasets

The following [global attributes](https://wcrp-cmip.github.io/cmip7-guidance/docs/CMIP7/Global_Attributes/) are considered when selecting a parent dataset:
https://github.com/Climate-REF/climate-ref/blob/9e7c5c056e165aded8105731a9658cec7a96e2dc/packages/climate-ref-core/src/climate_ref_core/constraints.py#L637-L641

This will likely result in the wrong matches because it is not sufficiently constrained. I would suggest adding `frequency`, `branding_suffix`, and `region`.