Update oes_types.h

Fix some compilation issues at oes_types.h:

1. Added #ifndef header.
2. Fix oes_access_cmd compilation issue.
3. Fix compilation issue at struct oes_l3_interface
4. Fix struct oes_ip_prefix
5. Fix struct oes_mc_route_data
6. Move oes_event_data and oes_event_info after oes_event_fdb