Vanilla Radio/Checkbox: add option for layout

Allows to configure the previously hard coded flex direction of the
'RadioGroup' React Vanilla renderer via the new UI Schema option
'orientation: "horizontal" | "vertical"'.

Author: rsoika

packages/examples/src/examples/radioGroup.ts

@@ -55,7 +55,8 @@ const schema = {
            type: 'Control',
            scope: '#/properties/exampleRadioEnum',
            options: {
-             format: 'radio'
+             format: 'radio',
+             orientation: 'vertical'
            }
          }
        ]

packages/vanilla-renderers/src/controls/RadioGroup.tsx

@@ -73,7 +73,7 @@ export const RadioGroup = ({
   if (hasRadioClass) {
     groupStyle = {
       display: 'flex',
-      flexDirection: 'row'
+      flexDirection: ('vertical' === appliedUiSchemaOptions.orientation) ? 'column' : 'row'
     };
   }
   return (
@@ -90,7 +90,6 @@ export const RadioGroup = ({
           appliedUiSchemaOptions.hideRequiredAsterisk
         )}
       </label>
-
       <div className={radioControl} style={groupStyle}>
         {options.map(option => (
           <div key={option.label} className={radioOption}>