implement embedding generation in supported inference providers (#589)

This PR adds the ability to generate embeddings in all supported
inference providers.

```
pytest -v -s llama_stack/providers/tests/inference/test_embeddings.py -k "bedrock" --inference-model="amazon.titan-embed-text-v2:0"  --env EMBEDDING_DIMENSION=1024

 pytest -v -s -k "vllm"  --inferrence-model="intfloat/e5-mistral-7b-instruct"  llama_stack/providers/tests/inference/test_embeddings.py --env EMBEDDING_DIMENSION=4096  --env VLLM_URL="http://localhost:9798/v1"

pytest -v -s --inference-model="nomic-ai/nomic-embed-text-v1.5"  llama_stack/providers/tests/inference/test_embeddings.py  -k "fireworks"  --env FIREWORKS_API_KEY=<API_KEY>--env EMBEDDING_DIMENSION=128

pytest -v -s --inference-model="togethercomputer/m2-bert-80M-2k-retrieval"  llama_stack/providers/tests/inference/test_embeddings.py  -k "together"  --env TOGETHER_API_KEY=<API_KEY>--env EMBEDDING_DIMENSION=768

pytest -v -s -k "ollama"  --inference-model="all-minilm:v8"  llama_stack/providers/tests/inference/test_embeddings.py --env EMBEDDING_DIMENSION=384

 torchrun $CONDA_PREFIX/bin/pytest -v -s -k "meta_reference" --inference-model="sentence-transformers/all-MiniLM-L6-v2"  llama_stack/providers/tests/inference/test_embeddings.py --env EMBEDDING_DIMENSION=384

```

llama_stack/providers/remote/inference/fireworks/config.py

@@ -13,7 +13,7 @@ from pydantic import BaseModel, Field
 @json_schema_type
 class FireworksImplConfig(BaseModel):
     url: str = Field(
-        default="https://api.fireworks.ai/inference",
+        default="https://api.fireworks.ai/inference/v1",
         description="The URL for the Fireworks server",
     )
     api_key: Optional[str] = Field(
@@ -24,6 +24,6 @@ class FireworksImplConfig(BaseModel):
     @classmethod
     def sample_run_config(cls) -> Dict[str, Any]:
         return {
-            "url": "https://api.fireworks.ai/inference",
+            "url": "https://api.fireworks.ai/inference/v1",
             "api_key": "${env.FIREWORKS_API_KEY}",
         }

llama_stack/providers/remote/inference/fireworks/fireworks.py

@@ -4,7 +4,7 @@
 # This source code is licensed under the terms described in the LICENSE file in
 # the root directory of this source tree.
 
-from typing import AsyncGenerator
+from typing import AsyncGenerator, List, Optional, Union
 
 from fireworks.client import Fireworks
 from llama_models.datatypes import CoreModelId
@@ -28,6 +28,7 @@ from llama_stack.providers.utils.inference.openai_compat import (
 from llama_stack.providers.utils.inference.prompt_adapter import (
     chat_completion_request_to_prompt,
     completion_request_to_prompt,
+    content_has_media,
     convert_message_to_dict,
     request_has_media,
 )
@@ -89,17 +90,19 @@ class FireworksInferenceAdapter(
     async def shutdown(self) -> None:
         pass
 
-    def _get_client(self) -> Fireworks:
-        fireworks_api_key = None
+    def _get_api_key(self) -> str:
         if self.config.api_key is not None:
-            fireworks_api_key = self.config.api_key
+            return self.config.api_key
         else:
             provider_data = self.get_request_provider_data()
             if provider_data is None or not provider_data.fireworks_api_key:
                 raise ValueError(
                     'Pass Fireworks API Key in the header X-LlamaStack-ProviderData as { "fireworks_api_key": <your api key>}'
                 )
-            fireworks_api_key = provider_data.fireworks_api_key
+            return provider_data.fireworks_api_key
+
+    def _get_client(self) -> Fireworks:
+        fireworks_api_key = self._get_api_key()
         return Fireworks(api_key=fireworks_api_key)
 
     async def completion(
@@ -264,4 +267,19 @@ class FireworksInferenceAdapter(
         model_id: str,
         contents: List[InterleavedTextMedia],
     ) -> EmbeddingsResponse:
-        raise NotImplementedError()
+        model = await self.model_store.get_model(model_id)
+
+        kwargs = {}
+        if model.metadata.get("embedding_dimensions"):
+            kwargs["dimensions"] = model.metadata.get("embedding_dimensions")
+        assert all(
+            not content_has_media(content) for content in contents
+        ), "Fireworks does not support media for embeddings"
+        response = self._get_client().embeddings.create(
+            model=model.provider_resource_id,
+            input=[interleaved_text_media_as_str(content) for content in contents],
+            **kwargs,
+        )
+
+        embeddings = [data.embedding for data in response.data]
+        return EmbeddingsResponse(embeddings=embeddings)