Add namespaces to macros defining hardfork versions
Omitted namespaces in macros caused problems with using them outside of those namespaces. To workaround problem user had to explicitly use omitted namespaces with
using hive::protocol::hardfork_version;
auto version = HIVE_HARDFORK_0_1_VERSION;
or
auto version = hive::protocol::HIVE_HARDFORK_0_1_VERSION;
All above are bad, so now all these workarounds are not needed and normal
HIVE_HARDFORK_0_1_VERSION
will work.