src: remove redundant OpenSSLBuffer

Replace the OpenSSLBuffer utility with ByteSource and
remove OpenSSLBuffer.

Signed-off-by: James M Snell <jasnell@gmail.com>

PR-URL: https://github.com/nodejs/node/pull/35663


Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>