record_curses: add test for newly added files

We have a UI bug where toggling a newly added file twice in the curses
interface didn't mark it as selected. This test checks that the underlying
logic is working as expected, the next patch of the series fixes the UI bug.

tests/test-commit-interactive-curses.t

@@ -181,4 +181,23 Editing patch of newly added file
   This is the second line
   This is the third line
 
+Newly added files can be selected with the curses interface
 
+  $ hg update -C .
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ echo "hello" > x
+  $ hg add x
+  $ cat <<EOF >testModeCommands
+  > TOGGLE
+  > TOGGLE
+  > X
+  > EOF
+  $ hg st
+  A x
+  ? editor.sh
+  ? testModeCommands
+  $ hg commit -i  -m "newly added file" -d "0 0"
+  $ hg st
+  ? editor.sh
+  ? testModeCommands
+