pinentry integration for keepassxc-cli

[Damglador]

GPG has a neat integration with pinentry, which allows entering passwords to GPG keys from a desktop-specific GUI. On top of that, at least Qt front-end has an option to save the password into the system keyrind, which allows pass, as it uses gpg for password encryption, to spit out passwords without having to enter a password every time as long as pinentry and session keyring are active. Would be neat to have to in keepassxc-cli as well