Remove native security group api class

There are native security group api classes define in the v2 and
v2.1 security_groups extension. Those classes in two extensions
are same. So remove the duplicated code, move those exception raising
into the base class.

Change-Id: I5e62ec8236e9d0e9601be652df7b8abf1828fbad
Merge "Remove native security group api class"