feat: github-auth flag (#4926)

* feat: github-auth flag

This will allow injecting credentials into code-server if you already
have them.

* Update Code

Contains the GitHub auth changes.

* Add e2e test for GitHub token

test/e2e/codeServer.test.ts

@@ -2,7 +2,7 @@ import { promises as fs } from "fs"
 import * as path from "path"
 import { describe, test, expect } from "./baseFixture"
 
-describe("CodeServer", true, [], () => {
+describe("CodeServer", true, [], {}, () => {
   test("should navigate to home page", async ({ codeServerPage }) => {
     // We navigate codeServer before each test
     // and we start the test with a storage state