emergency: make sure console password agents don't interfere with the emergency shell

emergency: make sure console password agents don't interfere with the emergency shell

If for any reason local-fs.target fails at startup while a password is
requested by systemd-cryptsetup@.service, we end up with the emergency shell
competing with systemd-ask-password-console.service for the console.

This patch makes sure that:

 - systemd-ask-password-console.service is stopped before entering in emergency
   mode so it won't make any access to the console while the emergency shell is
   running.

 - systemd-ask-password-console.path is also stopped so any attempts to restart
   systemd-cryptsetup in the emergency shell won't restart
   systemd-ask-password-console.service and kill the emergency shell.

 - systemd-ask-password-wall.path is stopped so
   systemd-ask-password-wall.service won't be started as this service pulls
   the default dependencies in.

Fixes: #10131