CupertinoTextfield control

[ndonkoHenri]

Closes #2376

TestCode:

import flet as ft


def main(page: ft.Page):
    page.window_always_on_top = True
    page.theme_mode = ft.ThemeMode.LIGHT

    page.add(
        ft.CupertinoTextField(
            bgcolor=ft.colors.BLUE_100,
            shadow=ft.BoxShadow(color=ft.colors.RED_400, blur_radius=5, spread_radius=5),
            on_change=lambda e: print("CupertinoTextField change = ", e.control.value),
            placeholder_text="Enter text here",
            suffix=ft.Icon(ft.icons.EDIT),
            suffix_visibility_mode=ft.VisibilityMode.EDITING,
        ),
    )


ft.app(target=main)