Model loading

[tigranfah]

A few of key things are implemented

• slight modification of the json processing code, the json str is explicitly parsed under a. try except block, because the previous implementation raise an Exception connected to not being able to parse the json string.
• tune the config files for the maximization of training throughput and reproduction training for chemlactica 125m and 1.3b trainings, add gradient clipping after each forward pass to prevent overflows
• add a debug config for chemlactica model for debugging purposes

[philippguevorguian]

lgtm