Enhancement: Add checkbox example into UI

[saicheck2233]

Description: Add checkbox example together with radio example into UI with the schema as below:

"checkbox": {
            "type": "boolean",
            "format": "checkbox",
            "title": "Transportation",
            "required": true,
            "enum": [
                "Vehicle",
                "Airplane",
                "Cruise"
            ]
        }

Changes:

The example schema use to generate radio button and checkbox.

The generated form with radio button and checkbox.