Fix all the issues reported by esctest2

[davidrg]

esctest2 is an automated test suite for terminal emulators, available here: https://github.com/ThomasDickey/esctest2/

It knows about xterm and iTerm2 but this mostly seems to be for the purpose of excluding tests that are known to not work (due to implemented features, etc). This results in some features CKW supports not being tested, and many features CKW does not support (or does not implement "correctly") being tested. So I adjusted escargs.py to add a CKW option allowing every test to be run.

The test was run three times as below:

./esctest.py --expected-terminal ckw --logfile ckw.txt
./esctest.py --expected-terminal xterm --logfile xterm.txt
./esctest.py --expected-terminal iterm2  --logfile iterm2.txt

And as of 2023-05-07, when run against CKW using the three "expected-terminal" options, the results were:

	CKW	XTerm	iTerm2
Passed Tests	123	113	87
Known bugs (skipped tests)	0	37	249
Failed Tests	429	402	216

So it appears CKW passes some tests that iTerm2 fails, but it fails many tests that xterm passes.

Ideally CKW would pass all of these tests if we wanted to add an xterm emulation option (#193). And really we should at a minimum pass all the tests that are not testing for specific xterm things.