Spring-ai Remove embedding from Document

This was a design decision way back taken from how langchain (python) was designed. In practice, this doesn't seem useful. It acts like a sort of cache, if you are writing the same document to the vector store multiple times, which doesn't seem realistic. If you have a use case for keeping the embedding in the Document, please comment.

Comment From: ThomasVitale

The SimpleVectorStore relies on the presence of the "embedding" field in Document.

Comment From: iAMSagar44

The AzureVectorStore also relies on the presence of the "embedding" field in Document. The doAdd method has the following line of code in the 1.0.0-M4 version of Spring AI. searchDocument.put(EMBEDDING_FIELD_NAME, document.getEmbedding());

Comment From: ilayaperumalg

The SimpleVectorStore relies on the presence of the "embedding" field in Document.

This PR https://github.com/spring-projects/spring-ai/pull/1822 addresses this.

Comment From: markpollack

We need to review all the vector store impls and make appropriate modifications. I noticed the Neo4jVectorStore also uses the 'getEmbeddings' method as sort of simple data structure to pass things along while adding. It can be refactored.

Comment From: ThomasVitale

If possible, it would be great to get https://github.com/spring-projects/spring-ai/pull/1794 merged before start removing the "embedding" field, mostly to avoid many many merge conflicts since they touch the same code area 😅

Comment From: ilayaperumalg

We need to review all the vector store impls and make appropriate modifications. I noticed the Neo4jVectorStore also uses the 'getEmbeddings' method as sort of simple data structure to pass things along while adding. It can be refactored.

Created https://github.com/spring-projects/spring-ai/issues/1826 to track this.