Improve CMIP7 support for diagnostics that require a parent dataset

There are several issues with the current CMIP7 support of diagnostics that require a parent dataset:

## ECS

The `update_recipe` method is not using the function `get_child_and_parent_dataset` for CMIP7 data, likely resulting in a wrong recipe:
https://github.com/Climate-REF/climate-ref/blob/9f5541a11999269946dc1d7b9610025b79a6efbc/packages/climate-ref-esmvaltool/src/climate_ref_esmvaltool/diagnostics/ecs.py#L213-L236

## TCR and TCRE

The TCR and TCRE data requirements do not use the constraint `AddParentDataset`, likely resulting in the wrong input data being selected:
https://github.com/Climate-REF/climate-ref/blob/9f5541a11999269946dc1d7b9610025b79a6efbc/packages/climate-ref-esmvaltool/src/climate_ref_esmvaltool/diagnostics/tcr.py#L42-L84
https://github.com/Climate-REF/climate-ref/blob/9f5541a11999269946dc1d7b9610025b79a6efbc/packages/climate-ref-esmvaltool/src/climate_ref_esmvaltool/diagnostics/tcre.py#L77-L109