Spring-ai Add builder pattern to SimpleVectorStore

• Create SimpleVectorStoreBuilder which can be used to create the SimpleVectorStore instance
• Remove the field embeddingModel from SimpleVectorStore as it can be retrieved from AbstractObservationVectorStore
• Deprecate the existing SimpleVectorStore constructors and use the builder to instantiate it
• Fix the tests

Comment From: sobychacko

Closed via https://github.com/spring-projects/spring-ai/commit/8ce837482584a42ba4921e825cc58fba1c076f61