lib: refactor to use more primordials in internal/encoding.js

PR-URL: https://github.com/nodejs/node/pull/36480


Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Pooja D P <Pooja.D.P@ibm.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>