V1 breaking changes

[InesaFitsner]

Other breaking changes

• Alignment: use ft.Alignment.CENTER (and other Alignment constants) instead of ft.alignment.center.
• scroll_to(): key renamed to scroll_key; in control key should be key=ft.ScrollKey(<value>)
• ScrollableControl: on_scroll_interval renamed to scroll_interval
• Animation: instead of ft.animation.Animation use ft.Animation
• Tabs: instead of text: OptionalString and tab_content: Optional[Control] use label: Optional[StrOrControl])
• Pagelet: bottom_app_bar renamed to bottom_appbar
• page.client_storage changed to page.shared_preferences.
• Dialogs: page.show_dialog(dialog_name) instead of page.open(dialog_name); `page.pop_dialog() to close dialog
• NavigationDrawer: position property instead of page.drawer and page.end_drawer
• All buttons: no text property, use content instead
• NavigationRailDesctination: no label_content property, use label instead
• SafeArea.left, .top, .right, .bottom to SafeArea.avoid_intrusions_left, .avoid_intrusions_top, .avoid_intrusions_right, .avoid_intrusions_bottom.
• Badge: use label instead of text
• Padding, Margin: should have named, not positional arguments. For example, instead of ft.Padding.symmetric(0, 10) should be ft.Padding(vertical = 0, horizontal = 10)
• SegmentedButton: selected: List[str] instead of Optional[Set]. Example: selected=["1", "4"] instead of selected={"1", "4"}. TODO: support sets in flet V1
• CupertinoActionSheetAction, CupertinoDialogAction, CupertinoContextMenuAction: default instead of is_default_action; destructive instead of is_destructive_action
• ft.app(target=main) should be changed to ft.run(main) or ft.run(main=main).
• FilePicker is a service now and must be added to page.services to work. Also, it provides only async methods to open dialogs which return results right away -no "on_result" event anymore.
• DragTarget.on_will_accept is of DragWillAcceptEvent type with accept: bool field. Use e.accept instead of e.data. DragTarget.on_leave is of DragTargetLeaveEvent type with src_id field. Use e.src_id instead of e.data.
• Page.on_resized renamed to Page.on_resize.
• Card.color -> Card.bgcolor, Card.is_semantic_container -> Card.semantic_container
• Checkbox.is_error -> Checkbox.error.
• Chip.click_elevation -> Chip.press_elevation
• Markdown.img_error_content -> Markdown.image_error_content.
• Switch.label_style -> Switch.label_text_style.
• Tabs.is_secondary -> Tabs.secondary.
• BoxDecoration.shadow -> BoxDecoration.shadows.