Add more fallbacks when terminfo or fiddle is not available

[tompng]

Add xterm key bindings to comprehensive list. Add fallback escape sequence of cursor hide/show.
Reline works perfectly in xterm without fiddle and terminfo.

Add xterm kpp knp kdch1(kdch1 was already added) to comprehensive list because I think it is the most major ENV['TERM'] value.

Add cursor show/hide escape sequence fallback "\e[?25h" and "\e[?25l".
"\e[?#{number}#{enable ? 'h' : 'l'}" (Terminal private modes set and rest, DECSET DECRST) is a commonly used escape sequence. Even if terminal emulator does not recognize it, it will be just ignored. Note that GNU Readline always outputs DECSET of bracketed paste "\e[?2004h" even if TERM=dumb.

The value is slightly different from infocmp xterm. But I think simple one (just reset extension number 25 = cursor visibility) is safer on non-xterm environment.

$ infocmp xterm
#	Reconstructed via infocmp from file: /Applications/iTerm.app/Contents/Resources/terminfo/78/xterm
xterm|X11 terminal emulator,
	...
	civis=\E[?25l
	cnorm=\E[?12l\E[?25h
	cvvis=\E[?12;25h
	...

[ima1zumi]

👍