https://github.com/meta-llama/llama-stack-client-python/pull/238 updated
llama-stack-client to also support Open AI endpoints for embeddings,
files, vector-stores. This updates the test to test all configs --
openai sdk, llama stack sdk and library-as-client.
# What does this PR do?
Adds a new endpoint that is compatible with OpenAI for embeddings api.
`/openai/v1/embeddings`
Added providers for OpenAI, LiteLLM and SentenceTransformer.
## Test Plan
```
LLAMA_STACK_CONFIG=http://localhost:8321 pytest -sv tests/integration/inference/test_openai_embeddings.py --embedding-model all-MiniLM-L6-v2,text-embedding-3-small,gemini/text-embedding-004
```