Removed NDEBUG tracking for compiling tests in Release mode

[twdragon]

I am preparing this implementation to be distributed as a Debian package. It requires running all the available tests despite the Debug or Release build type being selected for CMake. The presence of NDEBUG definition tracking in the code removes this possibility because the absence of the _DUMMY_PROTO_ section in multiaddress_protocol_list.h allows successful compilation only when the tests are not compiled. Otherwise, the following error occurs:

/home/twdragon/src/libp2p-cpp/test/libp2p/transport/upgrader_test.cpp:76:38: error: no member named '_DUMMY_PROTO_1' in 'libp2p::multi::Protocol::Code'
      libp2p::multi::Protocol::Code::_DUMMY_PROTO_1,
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
/home/twdragon/src/libp2p-cpp/test/libp2p/transport/upgrader_test.cpp:77:38: error: no member named '_DUMMY_PROTO_2' in 'libp2p::multi::Protocol::Code'
      libp2p::multi::Protocol::Code::_DUMMY_PROTO_2,
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
2 errors generated.

This PR proposes removing NDEBUG tracking from the code so the tests would be compiled and run when CMAKE_BUILD_TYPE is set to Release.