refactor: moved embeddings to embeddings folder

.vscode/settings.json

packages/core/src/ServiceContext.ts

packages/core/src/embeddings/ClipEmbedding.ts

packages/core/src/embeddings/MultiModalEmbedding.ts

packages/core/src/embeddings/OpenAIEmbedding.ts

packages/core/src/embeddings/index.ts

packages/core/src/embeddings/types.ts

packages/core/src/embeddings/utils.ts

packages/core/src/index.ts

packages/core/src/storage/vectorStore/SimpleVectorStore.ts

packages/core/src/tests/CallbackManager.test.ts

packages/core/src/tests/Embedding.test.ts

packages/core/src/tests/utility/mockOpenAI.ts