lib: refactor crypto cipher/hash/curve getters

* refactor internal util.filterDuplicateStrings() to eliminate unused
  code paths
* `.indexOf()` -> `.includes()` in test
* more concise arrow functions

PR-URL: https://github.com/nodejs/node/pull/10682


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michal Zasso <targos@protonmail.com>