Lazy screens

[0.5.0] - 2022-11-20

Added

• Add get_child_by_id and get_widget_by_id, remove get_child #1146
• Add easing parameter to Widget.scroll_* methods #1144
• Added Widget.call_later which invokes a callback on idle.
• DOMNode.ancestors no longer includes self.
• Added DOMNode.ancestors_with_self, which retains the old behaviour of
  DOMNode.ancestors.
• Improved the speed of DOMQuery.remove.
• Added DataTable.clear
• Added low-level textual.walk methods.
• It is now possible to await a Widget.remove.
  #1094
• It is now possible to await a DOMQuery.remove. Note that this changes
  the return value of DOMQuery.remove, which used to return self.
  #1094
• Added Pilot.wait_for_animation
• Added Widget.move_child #1121
• Added a Label widget #1190
• Support lazy-instantiated Screens (callables in App.SCREENS) #1185
• Display of keys in footer has more sensible defaults #1213
• Add App.get_key_display, allowing custom key_display App-wide #1213

Changed

• Watchers are now called immediately when setting the attribute if they are synchronous. #1145
• Widget.call_later has been renamed to Widget.call_after_refresh.
• Button variant values are now checked at runtime. #1189
• Added caching of some properties in Styles object

Fixed

• Fixed DataTable row not updating after add #1026
• Fixed issues with animation. Now objects of different types may be animated.
• Fixed containers with transparent background not showing borders #1175
• Fixed auto-width in horizontal containers #1155
• Fixed Input cursor invisible when placeholder empty #1202
• Fixed deadlock when removing widgets from the App #1219