vocab mapper: allow all keys to be passed by the client

[josephjclark]

The vocab mapper currently expects an anthropic API key to be passed by the client request.

We should also enable the pinecone and openai keys to be passed in the request object too. It sort of looks like this is supposed to work in the vocab_mapper main function, but while the keys are tested they aren't fed through to the vectorstore.

Now, in the long run, it makes sense for client to send their anthropic and openai keys directly, because that basically let them pay for themselves.

Pinecone is a bit harder to justify, because the pinecone API key needs to give access to the embeddings database which loaded the datasets. In the short-medium term WE own this an WE control the embeddings, so this has to come from the Apollo server.

But enabling the pinecone key to be passed would let us work around #151 and get the demo working