Update resources handler to allow empty resource specifications

[sorelfitzgibbon]

I (or rather Claude) have written python scripts to convert from json to tsv and back again. In converting back to json processes without specification (many are in f2) are still included with empty brackets, examples below. I (Claude) could easily update to fix this, but it might be nice to have the same set of processes specified for each node with empty brackets showing that it's not defined.

        "call_sSNV_Strelka2": {
            "cpus": {
                "min": 2,
                "fraction": 1,
                "max": 2
            },
            "memory": {}
        },
        "call_sSNV_Mutect2": {
            "cpus": {},
            "memory": {}
        },

[yashpatel6]

This is worth discussing in NF WG though I'm not a big fan of leaving undefined items in the allocations as it ends up accumulating and requires specific logic to be maintained to handle them along with Nextflow's default behaviors