Support Input css

[suyulin]

Affected version

0.13.0

No same issues found.

• [X] Yes, I search all issues but not found.

Steps to Reproduce

Support css for input padding,background-color.etc.

Code example

webf code

  final double _defaultPadding = 0;

  Widget _createInputWidget(BuildContext context) {
    FlutterFormElementContext? formContext = context.dependOnInheritedWidgetOfExactType<FlutterFormElementContext>();
    onChanged(String newValue) {
      setState(() {
        InputEvent inputEvent = InputEvent(inputType: '', data: newValue);
        dispatchEvent(inputEvent);
      });
    }

    InputDecoration decoration = InputDecoration(
        label: label != null ? Text(label!) : null,
        border: InputBorder.none,
        isDense: true,
        isCollapsed: true,
        contentPadding: EdgeInsets.fromLTRB(0, _defaultPadding, 0, _defaultPadding),

Expected results

all css effect

Actual results

Only some css is supported