chore: move vector stores to their own packages (#1605)

.changeset/long-insects-collect.md

examples/package.json

packages/llamaindex/package.json

packages/llamaindex/src/vector-store/AstraDBVectorStore.ts

...s/llamaindex/src/vector-store/AzureAISearchVectorStore.ts

packages/llamaindex/src/vector-store/ChromaVectorStore.ts

packages/llamaindex/src/vector-store/MilvusVectorStore.ts

...es/llamaindex/src/vector-store/MongoDBAtlasVectorStore.ts

packages/llamaindex/src/vector-store/PGVectorStore.ts

packages/llamaindex/src/vector-store/PineconeVectorStore.ts

packages/llamaindex/src/vector-store/QdrantVectorStore.ts

packages/llamaindex/src/vector-store/UpstashVectorStore.ts

packages/llamaindex/src/vector-store/WeaviateVectorStore.ts

packages/llamaindex/src/vector-store/index.ts

packages/llamaindex/tests/package.json

packages/providers/storage/astra/package.json

packages/providers/storage/astra/src/AstraDBVectorStore.ts

packages/providers/storage/astra/src/index.ts

packages/providers/storage/astra/tsconfig.json

packages/providers/storage/chroma/package.json