Add radio button group element to plugin config page

[nooogent]

This PR adds the ability to use a group of radio buttons on Plugin config pages.

Can be used as follows in a plugin UIConfig.json file:

   {
      "id": "myRadioId",
      "element": "radio",
      "options": [
        {
          "label":"TRANSLATE.OPTION_ONE",
          "name": "optionOne",
          "value": "1"
        },
        {
          "label":"TRANSLATE.OPTION_TWO",
          "name": "optionTwo",
          "value": "2"
        }
      ],
      "value": "1",
      "label": "TRANSLATE.MY_RADIO_LABEL"
    }

When the section is saved the value returned for the element will be the value of the selected option.

myplugin.prototype.setUIConfig = function (data) {
config.set('myConfigItem', data['myRadioId']);
}

Setting the value of the radio element in the plugin controller will result in the correct radio option being selected when the plugin config page is loaded.

myplugin.prototype.getUIConfig = function () {
var lang_code = this.commandRouter.sharedVars.get('language_code');
return this.commandRouter.i18nJson(_dirname + '/i18n/strings' + lang_code + '.json',
__dirname + '/i18n/strings_en.json',
__dirname + '/UIConfig.json')
.then(function (uiconf) {
// radio button group element
uiconf.sections[0].content[0].value = config.get('myConfigItem');
return uiconf;
})
.fail(function () {
libQ.reject(new Error());
});
};

[Tristenax]

Hi, @nooogent,
thanks for the PR, you did a great job with the menu change when an option is selected but you should change the radio button with a dropdown menu.

Let me know what you think

[nooogent]

Thanks for the feedback @Tristenax

There are a number of reasons why I think that someone might want to use radio buttons rather than a dropdown. For example in relation to the autostart plugin config page I think it makes sense because:

1. The options need to be emphasized, the options available are not homogeneous, so it's not like selecting a single dac from a list of dacs in a dropdown.
2. There are a small number of options.
3. The user doesn't have to open a dropdown to compare available options.
4. There is no obvious default option.

I actually tried to get the plugin-visible directive to work with the select element, but had no luck. I think it is because the "value" property of the selected element is a complex object rather than a value type.