Add support for new IBM models (labradorite and merlinite)

[shivchander]

Why are these changes needed?

Adding support for new IBM models based:

1. Labradorite-13b: https://huggingface.co/ibm/labradorite-13b
2. Merlinite-7b: https://huggingface.co/ibm/merlinite-7b

Checks

• [X] I've run format.sh to lint the changes in this PR.
• [X] I've included any doc changes needed.
• [X] I've made sure the relevant tests are passing (if applicable).

[abhi1092]

Hi @infwinston , could you review this PR?

[infwinston]

actually, can you resolve conflicts?

[abhi1092]

Thanks for reviewing the PR @infwinston. I resolved all the conflicts. Can we also send you the API endpoint for the Merlinite model to run the mt-bench for the leaderboard?

[DAOTHITHUY1]

Hello I'm my Thúy