This simple patch adds support for storing the HTTP error description
that Vector Store client receives from vector store. Until now it was
just printed to the log but it was not returned. For this reason it
was not forwarded to the drivers which forced users to access ScyllaDB
server logs to understand what is wrong with Vector Store.
This patch also updates formatter to print the message next to the
error code.
Fixes: VECTOR-189
d27610f138