sim-lib: Get rid of nested json for node definition

[sr-gi]

I must have been way more sleep-deprived than I thought when originally designing this, but we don't really need the nested json with node type tags to parse node information (as long as the node info has, at least one different field name).

Mainly, this goes from:

"nodes": [
    {
        "LND": {
            "id": "...",
            "address": "...",
            "macaroon": "...",
            "cert": "..."
        }
    },
    {
        "CLN": {
            "id": "...",
            "address": "...",
            "ca_cert": "...",
            "client_cert": "...",
            "client_key": "..."
        }
    }
]

To:

"nodes": [
    {
        "id": "...",
        "address": "...",
        "macaroon": "...",
        "cert": "..."
    },
    {
        "id": "...",
        "address": "...",
        "ca_cert": "...",
        "client_cert": "...",
        "client_key": "..."
    }
]

[carlaKC]

Let's get this done with high priority if we're going to change it, told the warnet folks to wait on a stable config file before they proceed.

[sr-gi]

Let's get this done with high priority if we're going to change it, told the warnet folks to wait on a stable config file before they proceed.

On it

[sr-gi]

@carlaKC should be good now