Enable detached mode and add ability to skip exposing individual channels on Shelly 2 and 2.5

[BMDan]

This PR enables device configurations like this (for two 2.5s):

[
    {
        "id": "0123456789ABCD",
        "channels": [
            {},
            {
                "type": "detachedContactSensor"
            }
        ]
    },
    {
        "id": "FEDCBA986754",
        "type": "detachedContactSensor",
        "channels": [
            {
                "type": "skip"
            }
        ]
    }
]

It also enhances logging in a few useful spots, and adds a hint for how to get describe to work for those who have enabled HTTP auth.

Tested only insofar as my little setup enables me to test. I apologize in advance for the crimes I have doubtless committed against idiomatic Node; I plead ignorance and a genuine belief that working, ugly code is better than no code at all.

Closes #87
Relevant to (but doesn't yet close) #219

[aschempp]

Does this "skipping" maybe conflict with #306 ?

[BMDan]

Does this "skipping" maybe conflict with #306 ?

Yup. We're going a similar direction, though. If either of these get merged, the other of us should just rebase.

Alternatively, IMHO, yours is a clearly better implementation, but I prefer my own data structure (maps where the keyspace is dense, small and numeric give me fits 🤣 ). If you switch to arrays to describe the channels, I'd rebase atop yours immediately.

[aschempp]

I actually considered using an array, but the problem is that you can't configure channel 3 without configuring channel 0, 1, 2 then. What's your opinion on that?

[BMDan]

I actually considered using an array, but the problem is that you can't configure channel 3 without configuring channel 0, 1, 2 then. What's your opinion on that?

My approach is to allow null (or { }, if that happens to be your preference) as a perfectly valid array entry, signifying "no overrides tor this channel". Not saying that's the prettiest solution, so I'm open to better approaches, but I think it is at least somewhat intuitive both at configuration-time and subsequently when reading.

[aschempp]

Thats a clever idea! I can see to adopt that asap 😊

[aschempp]

I just checked my code. Appart from the JSON schema and README, I think array syntax and null value is already fully supported, since there's no differences on accessing foo[0] whether that's an array or object. Or maybe I'm missing something?

[Krillle]

@BMDan Great addition. I would love to see the same for Shelly UNI
I feel like it would be easy with a few lines of code to enable detached mode and add ability to skip exposing individual channels on Shelly UNI as well. Yet the changes are too complex to find the right lines right away. Could you give me some hints?

[BMDan]

I ended up abandoning this project in favor of https://github.com/mongoose-os-apps/shelly-homekit, which seems to be far more stable, if a bit more of a bear to set up initially. @alexryd is still welcome to merge the code, of course, but I won't be updating it further.