Add optimized positional multi head stateless net (rnn-t decoder).

[fedorovgv]

What does this PR do ?

This is an optimized (without loops) version of stateless net for transducer decoder model.

Collection: ASR

Changelog

• Add specific line by line info of high level changes in this PR.

Usage

• You can potentially add a usage example below

# Add a code snippet demonstrating how to use this 

Jenkins CI

To run Jenkins, a NeMo User with write access must comment jenkins on the PR.

Before your PR is "Ready for review"

Pre checks:

• [ x] Make sure you read and followed Contributor guidelines
• Did you write any new necessary tests?
• Did you add or update any necessary documentation?
• Does the PR affect components that are optional to install? (Ex: Numba, Pynini, Apex etc)
• Reviewer: Does the PR have correct import guards for all optional libraries?

PR Type:

• [ x] New Feature
• Bugfix
• Documentation

Who can review?

Additional Information

• Related to # (issue)

[github-actions]

This PR is stale because it has been open for 14 days with no activity. Remove stale label or comment or update or this will be closed in 7 days.

[github-actions]

This PR was closed because it has been inactive for 7 days since being marked as stale.