ASR patches for v1.0.0
@okuchaiev fyi regarding the dockerfile ignore and correctly updating the self.trainer inside set_trainer.
# Bugfixes
- Correct WER calculation for RNNT by resetting the metric after each computation.
- Prevent numba from performing a sync across PT cuda stream simply to initialize a cost vector.
- Correctly update the trainer value using `set_trainer`
- Adds .nemo and .ckpt files to dockerignore

# Additions
- Adds RNNT global flags to enable detached gradient normalization of encoder, decoder and joint models
- Adds `weights_init_scale` and `hidden_hidden_bias_scale` values (default to original values) to attempt reduction in variance between runs
- Add `tds_uniform` and `tds_normal` initialization modes for Jasper based models.
