Unify the case, punctuation and name of test case keywords so they can
be more easily selected or skipped when desired. Add a few keywords that
were missing. Fix a couple of typos in test names.
- make sure that a match that returns a username also returns a
password, that should be blank if no password is found
- fix handling of multiple logins for same host where the password/login
order might be reversed.
- reject credentials provided in the .netrc if they contain ASCII control
codes - if the used protocol does not support such (like HTTP and WS do)
Reported-by: Harry Sintonen
Add test 478, 479 and 480 to verify. Updated unit 1304.
Closes#15586
