misc: replace Any with precise types

Curses screens, windows and pads are typed as curses.window, and the
widgets that may get no parent window take curses.window | None.

- EventHandler is generic over a ParamSpec, so each handler declares
  the arguments it passes, and MenuView is generic over the item its
  on_confirm hands out. Choice callbacks take no arguments.
- Scrollable is generic over its items, which DataTable and ListBox
  fix to tuple[str, str] and str.
- random.choice() and choice_low() are generic over the sequence, so
  the casts at their call sites are gone. BasicUserInterface.menu()
  and util.first() are generic too.
- Signal callbacks and their payloads are Callable[..., object] and
  object, since emit() only forwards them.
- JSON values in game_data are object and narrowed by isinstance,
  and data files are Traversable.
- Signal handlers take an int and a FrameType | None, and
  list_players() takes a TextIO.
- The focus_standout() context managers return
  Generator[None, None, None].

Any remains in three places: Player.__setstate__, whose pickled
__dict__ holds values of every type; Focusable.__init__, a mixin that
passes *args and **kwargs through to the next class; and the values
load_game_data() collects, whose element type depends on the field
each one fills.

pqcli/ui/curses/widgets/data_table.py

@@ -1,15 +1,14 @@
 import curses
-from typing import Any
 
 from pqcli.ui.curses.colors import COLOR_HIGHLIGHT, has_colors
 
 from .scrollable import Scrollable
 
 
-class DataTable(Scrollable):
+class DataTable(Scrollable[tuple[str, str]]):
     def __init__(
         self,
-        parent: Any,
+        parent: curses.window | None,
         h: int,
         w: int,
         y: int,
@@ -19,7 +18,6 @@ class DataTable(Scrollable):
         super().__init__(parent, h, w, y, x)
 
         self._align_right = align_right
-        self._items: list[tuple[str, str]]
         self._selected: int | None = None
 
     def add(self, text: str, value: str) -> None: