Fix multi dataloader and ASR logging + patch asr wer calculation
# Changelog
- Patch multidataloader to add all of the keys from the validation / test steps.
- Add the default `val/test` log results, where default is designated by `val_dl_idx` or `test_dl_idx` (optional keys in the *_ds configs which default to the 0th dataloader).
- Patch ASR wer computation. 
  - It was computing wer two times, which impacts execution time and causes logs to be printed twice.
- Patch all subclasses of `training_step` to automatically remove all log dicts and simply use the new logging api in place.

Signed-off-by: smajumdar <titu1994@gmail.com>