Openai embeddings 3 (#445)

.changeset/famous-singers-shake.md

examples/vectorIndexEmbed3.ts

package.json

packages/core/package.json

packages/core/src/constants.ts

packages/core/src/embeddings/OpenAIEmbedding.ts

packages/core/src/llm/LLM.ts

packages/core/src/llm/azure.ts

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

pnpm-lock.yaml