Generated C++ code missing some instances of SBE_CONSTEXPR

[aschw]

For example, it would be helpful if this line were marked SBE_CONSTEXPR:

simple-binary-encoding/sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/cpp/CppGenerator.java

Line 2623 in f426ec0

indent + " SBE_NODISCARD const char *%1$s() const\n" +