Don't allow new-ui to start the TUI

The TUI can't really work properly with new-ui, at least not as
currently written.  This patch changes new-ui to reject an attempt.
Attempting to make a DAP ui this way is also now rejected.

Regression tested on x86-64 Fedora 38.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29273
Approved-By: Andrew Burgess <aburgess@redhat.com>
7 files changed