Some implementation issues regarding chronosx

[BobWang21]

I have some questions about the implementation of following code

It seems that only the "counter" for 'input_injection_block_decoder' is being used.
Besides，"past_covariates" and "shifted_future_covariates" must have same shape

https://github.com/amazon-science/chronos-forecasting/blob/chronosx/src/chronosx/chronosx.py

[abdulfatir]

@melopeo can you help answer this?