fanquake authored Jul 05, 2024 and Calin Culianu committed Jul 05, 2024

Co-authored-by: Calin Culianu <calin.culianu@gmail.com>

This comes from [Core#17165](https://github.com/bitcoin/bitcoin/pull/17165)
Modified for BCHN.

Motivation for this: BIP70 is a security risk, and it also is nice to
have fewer dependencies on OpenSSL

Eventually we can bring in more backports that remove OpenSSL deps entirely
(because after this MR, the last remaining dep is regarding some system
random number generation which Core has found alternatives for).

Original commiter message:

    This removes BIP70 support. It also removes OpenSSL linking from Qt and
    building OpenSSLs lib_ssl in depends, as well as SSL lib detection from
    the build system. It's something that I'd optimistically like to do for
    0.20.0.