read the GDSII file, and find the layer/xy of specified text of certain cell.
output file is as following:
CELL uhd_char_r16c8
wl_oph6 4.74 1.895 metal3
wl_oph7 4.74 2.165 metal3
wl_oph8 4.74 2.43 metal3
wl_oph9 4.74 2.705 metal3
wl_oph10 4.74 2.975 metal3
wl_oph11 4.74 3.245 metal3
wl_oph12 4.74 3.515 metal3
wl_oph13 4.74 3.78 metal3