API: Add school field and filter in idols
API: Add school field and filter in idols

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