[Frontend] Support embeddings in the run_batch API

[pooyadavoodi]

Currently run_batch which is the offline batching API only supports chat completion. This PR adds embedding supports to run_batch. The PR also adds support for empty lines (or lines with only whitespace) in the input file of run_batch.

[github-actions]

👋 Hi! Thank you for contributing to the vLLM project.
Just a reminder: PRs would not trigger full CI run by default. Instead, it would only run fastcheck CI which consists a small and essential subset of CI tests to quickly catch errors. You can run other CI tests on top of default ones by unblocking the steps in your fast-check build on Buildkite UI.

Once the PR is approved and ready to go, please make sure to run full CI as it is required to merge (or just use auto-merge).

To run full CI, you can do one of these:

• Comment /ready on the PR
• Add ready label to the PR
• Enable auto-merge.

🚀

[wuisawesome]

Looks great, do you mind adding a simple example to examples/offline_inference_openai.md?

[pooyadavoodi]

Looks great, do you mind adding a simple example to examples/offline_inference_openai.md?

Thanks @wuisawesome
I updated the md file.
I wrote that vllm >= 0.5.5 is required as that's the next version that will be released. Is that okay?

[wuisawesome]

I wrote that vllm >= 0.5.5 is required as that's the next version that will be released. Is that okay?

Yep!