SparkNLP 997 Introducing QWEN2Transformer

[prabod]

Description

This PR introduce the QWEN family of LLMs

Qwen: comprehensive language model series

Qwen1.5 is the beta version of Qwen2, a transformer-based decoder-only language model
pretrained on a large amount of data. In comparison with the previous released Qwen, the
improvements include:

6 model sizes, including 0.5B, 1.8B, 4B, 7B, 14B, and 72B; Significant performance improvement
in Chat models; Multilingual support of both base and chat models; Stable support of 32K
context length for models of all sizes

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING page.
• I have added tests to cover my changes.
• All new and existing tests passed.