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/logout.test.ts

@@ -1,7 +1,7 @@
 // NOTE@jsjoeio commenting out until we can figure out what's wrong
 // import { describe, test, expect } from "./baseFixture"
 
-// describe("logout", true, [], () => {
+// describe("logout", true, [], {}, () => {
 //   test("should be able logout", async ({ codeServerPage }) => {
 //     // Recommended by Playwright for async navigation
 //     // https://github.com/microsoft/playwright/issues/1987#issuecomment-620182151