Add option to cookbook that returns recipes sorted by group

@jfrost-mo is already working on this.

Since Nov 12, 2025.

### What problem does your feature request solve?
`cset cookbook` returns a single list of recipes, without apparent order which makes it difficult to locate a specific recipe, and this is going to get worse as the number of recipes increase. It will be nice if the output could be sorted so similar recipes are close together, something like:
```
[ spatial plots ]
- generic_level_spatial_plot_aggregated_this_way
- generic_level_spatial_plot_aggregated_this_other_way
- example_spatial_plot
...
[ profiles ]
- generic_profile
- generic_profile_aggregated_this_way
...
```

### Describe the solution you'd like
This can probably be achieved easily by adding some metadata to the recipe yaml file (if not already there), and add the additional sort/group output capability to the cookbook command. It can be triggered by a command line option.

### Describe alternatives you've considered
There is a ticket regarding textualised output of the recipe, but not sure how much traction does it have or whether it will cover this case.