feat: remove optional builtins prefixes from prelude functions

[trueNAHO]

No idea how easy or hard this is to implement, but it might be nice to have an option to remove optional builtins. prefixes for elements that are already in the prelude.

Maybe this option should be enabled by default and can be disabled in the configuration file.

This proposal is inspired by https://github.com/NixOS/nixpkgs/pull/444432, whose discussion continues at https://github.com/NixOS/nixpkgs/pull/449123.