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/event_handler.py

@@ -1,15 +1,17 @@
 from collections.abc import Callable
-from typing import Any
+from typing import Generic, ParamSpec
+
+P = ParamSpec("P")
 
 
-class EventHandler:
+class EventHandler(Generic[P]):
     def __init__(self) -> None:
-        self.callbacks: list[Callable[..., Any]] = []
+        self.callbacks: list[Callable[P, object]] = []
 
-    def __call__(self, *args: Any, **kwargs: Any) -> None:
+    def __call__(self, *args: P.args, **kwargs: P.kwargs) -> None:
         for callback in self.callbacks:
             callback(*args, **kwargs)
 
-    def __iadd__(self, callback: Callable[..., Any]) -> "EventHandler":
+    def __iadd__(self, callback: Callable[P, object]) -> "EventHandler[P]":
         self.callbacks.append(callback)
         return self