This version also handles some race conditions that were resulting in "...variable not
iterable..." responses that prevented proper display in the VARIABLES pane.

The main functional change is this version's ability to work with the COBOL ACCEPT statement.
All input and output is from the VSC "DEBUG CONSOLE" panel.  The debugging adapter, however,
keeps track of whether GDB thinks the inferior is *running or *stopped.  When *running, all
VSC attempts to talk to the inferior are inhibited, and any keyboard commands are stripped
of the '-interpreter-exec' wrapper and sent in raw form to the inferior.

This seems to work.

The C/C++ debugger for VSC works differently; it sets up pipes for stdin and stdout, which
are used for sending and receiving command information to GDB.  Meanwhile, the inferior's
TTY is redirected to the "Integrated Terminal" pane of VSC.  I didn't try to duplicate that
because I didn't want to take the time at this time, and because after several hours of
investigation I was unable to determine how to set the inferior's TTY to the integrated
terminal pane.