Trim crypto++

[alex-ozdemir]

Isolate our dependencies on crypto++.

First of all, this should (slightly) improve compile times.

Second, since the location of the crypto++ headers is platform-dependent, this includes will need to be macro-guarded, or something like that, so it makes sense to thin them out.

[chadbrewbaker]

Mind if I extend the branch for full AWSLinux2 support so gg can run from AWS Lambda? AWS Linux2 distro is still on protobuf2 and cmake 2. Probably out of scope but one user was complaining of nvcc compiler needing extra support, might just be a README tweak on which lines in the config to alter for other compilers.