Simplify mqttjson dict format

[wlcrs]

Description

I'm using the new mqqtjson option to integrate ebusd in to Home Assistant.

I'm however a bit surprised by how fields which contain multiple values are handled. I would propose to simplify how you return these fields, and remove those unnecessary {"name": ,"value":}.

In case of naming conflicts, you could suffix the index?

So instead of:

{
     "0": {"name": "temp1", "value": 53.0},
     "1": {"name": "temp1", "value": 51.0},
     "2": {"name": "temp2", "value": null},
     "3": {"name": "temp1", "value": null},
     "4": {"name": "temp1", "value": 48.0},
     "5": {"name": "pumpstate", "value": "off"}
}

Return this:

{
     "temp1_0": 53.0,
     "temp1_1": 51.0,
     "temp2": null,
     "temp1_3": null,
     "temp1_4:" null,
     "pumpstate": "off",
}

[john30]

the numbers are used because the names are not unique. so the right thing to do would be to correct the message definition to have unique fields names, then the numeric index is replaced by the name.

[Nico184]

Hello,
I tried to add the field namens in configuration files, but it did not work as expected, as I described here #255 of the configuration rep. Did I something wrong?

[john30]

with --mqttjson=short (commit 1798007) it is now possible to remove the extra object from the payload

[john30]

completed