Add configurabe authentication

[garrettjstevens]

This adds an extension point for configurable authentication. Draft for now, more info to come if this idea ends up working out.

[garrettjstevens]

One thing I tried to do with this is to allow users to not have to click on a login button if there is only a single login type configured. I realized, however, that if the login flow opens a popup window, like with Google or Microsoft, then without the explicit user interaction of clicking on the login button, the browser blocks the popup window. I therefore made it so that users can skip clicking a login button only if there is a single login type configured and it doesn't need a popup window (which only applies to guest login for the built-in types, but could apply to custom auth types).

[garrettjstevens]

I tried this out with a custom plugin. I manually added the header { 'X-Apollo-Custom': 'Test User;test@user.com' } to the login request, and it worked to create a user from that header. Here's the full plugin code:

import Plugin from "@jbrowse/core/Plugin";
import type PluginManager from "@jbrowse/core/PluginManager";
import type { Request } from "express";
import { version } from "../package.json";

export default class ApolloCustomAuthPlugin extends Plugin {
  name = "ApolloCustomAuthPlugin";
  version = version;

  apolloInstall(pluginManager: PluginManager) {
    pluginManager.addToExtensionPoint(
      "Apollo-RegisterCustomAuth",
      (
        customAuths: Map<
          string,
          {
            message: string;
            needsPopup: boolean;
            handler: (
              request: Request,
            ) => Promise<{ name: string; email: string }>;
          }
        >,
      ) => {
        customAuths.set("custom", {
          message: "Sign in with Custom Auth",
          needsPopup: false,
          handler: async (request: Request) => {
            const remoteUser = request.headers['x-apollo-custom'];
            if (!remoteUser || Array.isArray(remoteUser)) {
              throw new Error("Invalid remote user");
            }
            const [name, email] = remoteUser.split(";");
            return { name, email };
          },
        });
        return customAuths;
      },
    );
  }
}

Now I need to see if this works for a more complicated login type, e.g. an Oauth provider that's not Google or Microsoft.