curses: various fixes (#3771)

- fix arg names
- fix types based on default value
- mark positional-only args

tests/stubtest_whitelists/py38.txt

@@ -87,8 +87,6 @@ contextvars.Context.get
 contextvars.ContextVar.reset
 contextvars.ContextVar.set
 copy.PyStringMap
-curses.panel.new_panel
-curses.wrapper
 dataclasses.dataclass
 dataclasses.field
 dataclasses.make_dataclass

tests/stubtest_whitelists/py3_common.txt

@@ -256,8 +256,6 @@ curses.COLORS
 curses.COLOR_PAIRS
 curses.COLS
 curses.LINES
-curses.textpad.Textbox.__init__
-curses.textpad.Textbox.edit
 dbm.error
 dbm.ndbm
 decimal.DecimalException.handle