[netgroupman] Add GetMappedAS() and GetGroup()

These currently call through to the CNetAddr methods. The logic will be moved in a future commit.

src/netgroup.cpp

@@ -3,3 +3,13 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <netgroup.h>
+
+std::vector<unsigned char> NetGroupManager::GetGroup(const CNetAddr& address) const
+{
+    return address.GetGroup(m_asmap);
+}
+
+uint32_t NetGroupManager::GetMappedAS(const CNetAddr& address) const
+{
+    return address.GetMappedAS(m_asmap);
+}