changed how password is stored

[gvsabi]

I felt storing the password as plain text in the configuration file was unsecure, so I changed how the password is stored when connecting to lemmy (as that is what I use neonmodem for). Insted of plain text, it is now stored as a hash. To compare the hash with the user's actual password, I made it so that the program asks for the user's password every time they try to log in. If the password matches it will connect otherwise it will say the password did not match the hash. You can remove a couple of the fmt outputs as it was used for debugging purposes and is not really required now.

[mrusme]

Hey @gvsabi, thank you for the PR, however there's already an open PR for the password issue: https://github.com/mrusme/neonmodem/pull/29

If you feel like, please feel free to go through the discussions there, add your feedback and maybe even incorporate your changes!