CryptoManager::cct is now used in CephContext ctor. To provide this
defintion
any ceph_context.cc target must also include Crypto.cc.
crimson-alien-common library which only had ceph_context.cc must now
also include Crypto.cc.
However, the fact that crimson-common also includes Crypto.cc would
cause multiple defintions
to any Crypto classes methods.
To resolve this, let's wrap all Crypto classes with TOPNSPC::common that
would be forwarded using common_fwd logic.