r.horizon: change JSON format

[petrasovaa]

Given the discussions about JSON format, I decided to change it to:

[
    {
        "x": 635729.779412,
        "y": 223023.897059,
        "horizons": [
            {
                "azimuth": 0.000000,
                "angle": 3.389152,
                "distance": 270.000000
            },
            {
                "azimuth": 100.000000,
                "angle": 1.945799,
                "distance": 386.393582
            },
            {
                "azimuth": 200.000000,
                "angle": 2.586693,
                "distance": 458.802790
            }
        ]
    }
]

Before it was (#3534):

[
    {
        "x": 632431.824277,
        "y": 222607.442813,
        "azimuth": [
            50.000000,
            100.000000,
            150.000000,
            200.000000,
            250.000000,
            300.000000,
            350.000000
        ],
        "horizon_height": [
            0.031715,
            0.065790,
            0.084245,
            0.084245,
            0.008515,
            0.000000,
            0.000000
        ],
        "horizon_distance": [
         ....
        ]
    }
]

Importantly, this needs to get into 8.4 release.

[wenzeslaus]

The change in format is good and fits with what we are doing in v.info.

It would be good to have it in the release, so we don't release format which we don't want to use. However, it would be possible to make the change in a backward-compatible way.

[echoix]

Is this ready to merge? And the other JSON ones?

[neteler]

Importantly, this needs to get into 8.4 release.

So far it hasn't been backported. Shall I do that, @petrasovaa ?

[petrasovaa]

It was my intention to have it in 8.4.0... Thanks for noticing this...