Allow ANSI string terminator to work

Treat "\e]0;<title>\e\\" (set window title) the same way
it interprets "\e]0;<title>\007".

It seems that Konsole does not recognize the standard string terminator
sequence "\e\\" (ESC \). Everything works fine if I use "\007" (BEL).

<http://invisible-island.net/xterm/xterm.faq.html#how2_title>

Thanks to Aniketh Girish anikethgireesh gmail com and Martin Sandsmark
martin sandsmark kde org for patch/review

BUG:231405
REVIEW:129895