patch 9.0.1084: code handling low level MS-Windows events cannot be tested

Problem:    Code handling low level MS-Windows events cannot be tested.
Solution:   Add test_mswin_event() and tests using it. (Christopher Plewright,
            closes #11622)

src/term.c

@@ -827,7 +827,7 @@ static tcap_entry_T builtin_pcansi[] = {
 };
 
 /*
- * These codes are valid for the Win32 Console .  The entries that start with
+ * These codes are valid for the Win32 Console.  The entries that start with
  * ESC | are translated into console calls in os_win32.c.  The function keys
  * are also translated in os_win32.c.
  */