Resolve issue with building Crypto++ from source while performing library testing

[Alvov1]

Currently library testing is being mainly performed against Crypto++ library.

By default, Crypto++ writes noisy suffixes (h, o, '.') at the end while outputting numbers in std::streams. This behavior should be disabled for a proper testing.

Support for std::showbase (which is required to disable this nonsense) is only available when building Crypto++ from sources with CRYPTOPP_USE_STD_SHOWBASE preprocessor flag(define): https://github.com/chfast/cryptopp-1/blob/9cc01defde81e65503fbb1a5ba14693ecaa7fd1f/config.h#L104

Building library from sources on each workflow run is not a good idea, so it is reasonable to switch to another cryptography library like GMP