Update security/cryptopp to 7.0.0

We now install a pkgconfig file which will allow ports to check whether
cryptopp was built with assembly instructions enabled or not. There are
a few functions that will be undefined if built without assembly and
-DCRYPTOPP_DISABLE_ASM needs to be passed to the compiler in that case
to avoid build failures. This is not new, but the pkgconf file should
make it easier to determine if the flag is needed or not.

Fix several ports due to API changes and to use the new pkgconf file
to determine cryptopp location and build flags. Special cases below.

deskutils/cdcat

• Use cryptopp shared library instead of static, detect with pkgconf

devel/xeus

• Fix dependencies and remove header-only libraries from RUN_DEPENDS
• Rework to use the cryptopp pkgconf file
• net/cppzmq CMake files were fixed in r477649, remove hacks for that as they were seemingly causing devel/xeus-cling to link to cryptopp unnecessarily
• Remove C++17 code from cryptopp checks for compatibility

devel/xeus-cling

• Fix dependencies
• Remove hacks for previously broken cppzmq CMake files and no longer needed cryptopp dependency

Changes: https://www.cryptopp.com/#news
PR: 230579 (original patch, not used)
Submitted by: yuri