API: Add main_unit in idols objects
API: Add main_unit in idols objects

dburr/SchoolIdolAPI,rdsathene/SchoolIdolAPI,dburr/SchoolIdolAPI,dburr/SchoolIdolAPI,SchoolIdolTomodachi/SchoolIdolAPI,SchoolIdolTomodachi/SchoolIdolAPI,rdsathene/SchoolIdolAPI,SchoolIdolTomodachi/SchoolIdolAPI,rdsathene/SchoolIdolAPI