`labels.json` format

[eimrek]

Proposed format update for acwf_paper_plots/code-data/labels.json

demo:

{
    "references":
    {
        "all-electron average":
        {
            "oxides": "results-oxides-verification-PBE-v1-AE-average.json",
            "unaries": "results-unaries-verification-PBE-v1-AE-average.json"
        }
    },
    "methods":
    {
        "ABINIT":{
            "oxides": "results-oxides-verification-PBE-v1-abinit-PseudoDojo-0.5b1-PBE-SR-standard-psp8.json",
            "unaries": "results-unaries-verification-PBE-v1-abinit-PseudoDojo-0.5b1-PBE-SR-standard-psp8.json",
            "code_label": "ABINIT",
            "basis_set_label": "PW".
            "pseudo_label": "PseudoDojo-v0.5b",
            "is_main": true
        },
        ...
    }
}    

Comments:

• The dictionary key of each method is the short_label, e.g. "ABINIT".
• code, basis set and pseudopotential labels are separated into 3 separate keys.
• The separate dictionaries methods-main and methods-supplementary are merged into one (methods) and the key is_main determines if an entry is main or supplementary.