This PR moves the existing Oracle AI Vector Search integrations with LangChain to a new package named langchain-oracledb under libs/oracledb

The classes include:

• OracleDocLoader, OracleAutonomousDatabaseLoader: Load the documents from various sources
• OracleSummary: Summarize content within/outside the database
• OracleEmbeddings : Generate embeddings within/outside the database
• OracleTextSplitter: Chunk according to different requirements using Advanced Oracle Capabilities
• OracleVS: Store, index, and query vectors

More information on these classes can be found on Oracle AI Vector Search End-to-End Demo Guide.

Additionally, for OracleVS, following features are added:

• Database filtering
• Async functions