feat: add mongo db vector support with example

apps/mongodb/2_load_and_index.ts

apps/mongodb/3_query.ts

apps/mongodb/README.md

apps/mongodb/docs/1_signup.png

apps/mongodb/docs/2_connection_string.png

apps/mongodb/docs/3_vectors_in_db.png

apps/mongodb/docs/4_search_tab.png

apps/mongodb/docs/5_json_editor.png

apps/mongodb/docs/7_index_created.png

apps/mongodb/package.json

apps/mongodb/tinytweets.json

packages/core/src/Node.ts

packages/core/src/index.ts

packages/core/src/storage/index.ts

...s/core/src/storage/vectorStore/MongoDBAtlasVectorStore.ts

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

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

pnpm-lock.yaml