[EOSIO/eos] MacOS compilation error (#5302)

@lazaridiscom Of course the comment on #4244 seems related—it’s the same person with the same problem report.

For once, Homebrew is not at fault. There is something wrong with the XCode and framework installation. CMake’s `find_library()` function is used by the wallet plugin to determine the linking flags required for its build. Check permissions, check that the specific required frameworks really are present, check the filesystem for corruption. If none of those things help, file a problem report with CMake. The `find_library()` function works on any normal, healthy system.

Failing all of that, VirtualBox with a Linux installation has been reported to work by another Mac user with a permanently sick system.