fs: undeprecate lchown()

uv_fs_lchown() exists, as of libuv 1.21.0. fs.lchown() can now
be undeprecated. This commit also adds tests, as there were
none.

PR-URL: https://github.com/nodejs/node/pull/21498
Fixes: https://github.com/nodejs/node/issues/19868


Reviewed-By: Wyatt Preul <wpreul@gmail.com>