Add option to save optim state

config_EF_AC_Szada.yaml

config_EF_AC_Tiszadob.yaml

config_EF_OSCD.yaml

config_base.yaml

config_siamconc_AC_Szada.yaml

config_siamconc_AC_Tiszadob.yaml

config_siamconc_OSCD.yaml

config_siamdiff_AC_Szada.yaml

config_siamdiff_AC_Tiszadob.yaml

config_siamdiff_OSCD.yaml

src/core/trainers.py

src/train.py