Make Provider OAuthCallbackError easier to debug

[ctjlewis]

Goals

1. Make the error easier to debug.

Non-Goals

No response

Background

Got this vague error, spent a few minutes trying to figure it out:

[auth][error][OAuthCallbackError]: OAuth Provider returned an error. Read more at https://errors.authjs.dev#oauthcallbackerror
    at handleOAuth (webpack-internal:///(sc_server)/./node_modules/.pnpm/@auth+core@0.0.0-manual.8fcd46b0/node_modules/@auth/core/lib/oauth/callback.js:54:15)
    at async Module.callback (webpack-internal:///(sc_server)/./node_modules/.pnpm/@auth+core@0.0.0-manual.8fcd46b0/node_modules/@auth/core/lib/routes/callback.js:34:41)
    at async AuthInternal (webpack-internal:///(sc_server)/./node_modules/.pnpm/@auth+core@0.0.0-manual.8fcd46b0/node_modules/@auth/core/lib/index.js:103:38)
    at async Auth (webpack-internal:///(sc_server)/./node_modules/.pnpm/@auth+core@0.0.0-manual.8fcd46b0/node_modules/@auth/core/index.js:120:30)
    at async eval (webpack-internal:///(sc_server)/./node_modules/.pnpm/next@13.4.7-canary.1_react-dom@18.2.0_react@18.2.0/node_modules/next/dist/esm/server/future/route-modules/app-route/module.js:229:37)

Eventually manually inspected the requests and saw this for /api/auth/callback/github?...:

Query String Parameters

Key	Value
error	redirect_uri_mismatch
error_description	The redirect_uri MUST match the registered callback URL for this application.
error_uri	https://docs.github.com/apps/managing-oauth-apps/troubleshooting-authorization-request-errors/#redirect-uri-mismatch

It would be more efficient to tell the user the callback URL was misconfigured right there in stderr, rather than only:

OAuth Provider returned an error. Read more at https://errors.authjs.dev#oauthcallbackerror

Proposal

When the OAuth Provider errors, it should be possible to extract information from the query string and log it to stderr rather than making the developer check the request manually.

I may PR it depending on enthusiasm.