Introduces a builder pattern for configuring CassandraVectorStore instances and
moves the implementation to the org.springframework.ai.vectorstore.cassandra
package. This change:
- Makes configuration more flexible and type-safe through builder methods
- Improves code organization by moving to a dedicated vector store package
- Deprecates old constructors in favor of the builder pattern
- Adds comprehensive validation of configuration options
- Enables better IDE support through method chaining
- The builder pattern provides a more maintainable and user-friendly way to
configure vector stores while ensuring configuration validity at compile time.