GitLab

Adds some backward compatibility code so old inference code still works.

added across rank sync for checkpoint iteration laod, fixed type for timing, and validation iterations

- Accumulate encoder hidden state gradient to handle skip connection
- Correctly compute the number of layers in encoder / decoder for T5 model
- Ensure e weights are initialized the same way in embeddings
- Synchronize embedding gradients across encoder and decoder for T5 model
- Support for checkpoint loading and saving