feat(model): Support Qwen2.5 models

[fangyinc]

Description

Closes #2026

How Has This Been Tested?

First, download the model according to the link to the models directory of the project.

Then, modify your .env file

LLM_MODEL=qwen2.5-7b-instruct

Finally, restart the DB-GPT.

Snapshots:

Include snapshots for easier review.

Checklist:

• My code follows the style guidelines of this project
• I have already rebased the commits and make the commit message conform to the project standard.
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• Any dependent changes have been merged and published in downstream modules

[csunny]

LGTM

[Aries-ckt]

LGTM