Discovery API: Return distinct error message for queries over max length

[LtChae]

What

• Discovery API returns a 400 response and a descriptive error message when exceeding presto's max query length

Why

As a data consumer I would like to receive descriptive, actionable errors so that I can fix issues with queries I am developing.

Notes:

Queries are sent to presto in the header of the request.
See below for error example.

     {:ok,
         %Tesla.Env{
           __client__: %Tesla.Client{adapter: nil, fun: nil, post: [], pre: []},
           __module__: Prestige.Client.RequestStream,
           body: "<h1>Bad Message 431</h1><pre>reason: Request Header Fields Too Large</pre>",
           headers: [
             {"content-type", "text/html;charset=iso-8859-1"},
             {"content-length", "74"},
             {"connection", "close"}
           ],
           method: :post,
           opts: [],
           query: [],
           status: 431,
           url: "http://kdp-kubernetes-data-platform-presto.kdp:8080/v1/statement"
         }}

Tested with a query over 6900 characters