The `bwpass` command attempts to replicate the main functionality of
`pass` on top of `bw`. Since `bw` is incredibly slow, it tries to avoid
spawning it whenever possible by caching the list of items. It also
manages the Bitwarden CLI session by reading the session token from a
file. If the file does not exist, it will prompt for the vault master
password using `pinentry`, unlock the session, and store the new token.
