Files: userauth_kbd_packet.c, userauth_kbd_packet.h, test_keyboard_interactive_auth_info_request.c, userauth.c
Notes:
This refactors `SSH_MSG_USERAUTH_INFO_REQUEST` processing in `userauth_keyboard_interactive()` in order to improve robustness, correctness and readability or the code.
* Refactor userauth_keyboard_interactive to use new api for packet parsing
* add unit test for userauth_keyboard_interactive_parse_response()
* add _libssh2_get_boolean() and _libssh2_get_byte() utility functions
Credit:
xalopp
