ui/curses: add curses interface draft

pqcli/ui/curses/util.py

@@ -0,0 +1,13 @@
+import typing as T
+from dataclasses import dataclass
+
+
+@dataclass
+class Choice:
+    keys: T.List[int]
+    desc: str
+    callback: T.Callable[..., T.Any]
+
+
+def first(source: T.Iterable[T.Any], default: T.Any = None) -> T.Any:
+    return next(iter(source), default)