Support for file-uploader

[selka24]

Would be nice to have support for file uploader input Type:
{
"title": "Files",
"type": "object",
"properties": {
"file": {
"type": "string",
"format": "data-url",
"title": "Single file"
},
"files": {
"type": "array",
"title": "Multiple files",
"items": {
"type": "string",
"format": "data-url"
}
},
"filesAccept": {
"type": "string",
"format": "data-url",
"title": "Single File with Accept attribute"
}
}
}