ui: ensure `getpass()` returns bytes Previously, this could return either bytes or str. I'm not sure which direction we should go in, but since the input is bytes, I guess bytes makes sense as output. `debuguigetpass` crashed because it assumed bytes would be returned, `sslcontext.load_cert_chain()` is happy with bytes or str if the type info in PyCharm is correct, and `smtplib.SMTP.login()` wants str. I couldn't figure out how to test this, because the test stalls for input with `echo test | hg debuguigetpass --config ui.interactive=1`, likely because it drains stdin before prompting. The custom input reading with `ui.nontty=1` does not. I'm also a bit concerned with all of this encoding/decoding. The existing code in the mail module uses `encoding.strfromlocal()`, but the username and password are ascii encoded/decoded in `mercurial.url.passwordmgr.find_user_password()` with `pycompat.{str,bytes}url()`. I'm not sure if this inconsistency could cause subtle compatability issues. Differential Revision: https://phab.mercurial-scm.org/D9375