Implement last opened functionality (#4633)

* Implement last opened functionality

Fixes https://github.com/cdr/code-server/issues/4619

* Fix test temp dirs not being cleaned up

* Mock logger everywhere

This suppresses all the error and debug output we generate which makes
it hard to actually find which test has failed.  It also gives us a
standard way to test logging for the few places we do that.

* Use separate data directories for unit test instances

Exactly as we do for the e2e tests.

* Add integration tests for vscode route

* Make settings use --user-data-dir

Without this test instances step on each other feet and they also
clobber your own non-test settings.

* Make redirects consistent

They will preserve the trailing slash if there is one.

* Remove compilation check

If you do a regular non-watch build there are no compilation stats so
this bricks VS Code in CI when running the unit tests.

I am not sure how best to fix this for the case where you have a build
that has not been packaged yet so I just removed it for now and added a
message to check if VS Code is compiling when in dev mode.

* Update code-server update endpoint name

test/unit/node/routes/static.test.ts

@@ -1,7 +1,7 @@
 import { promises as fs } from "fs"
 import * as path from "path"
 import { rootPath } from "../../../../src/node/constants"
-import { tmpdir } from "../../../utils/helpers"
+import { clean, tmpdir } from "../../../utils/helpers"
 import * as httpserver from "../../../utils/httpserver"
 import * as integration from "../../../utils/integration"
 
@@ -23,8 +23,10 @@ describe("/_static", () => {
   let testFileContent: string | undefined
   let nonExistentTestFile: string | undefined
 
+  const testName = "_static"
   beforeAll(async () => {
-    const testDir = await tmpdir("_static")
+    await clean(testName)
+    const testDir = await tmpdir(testName)
     testFile = path.join(testDir, "test")
     testFileContent = "static file contents"
     nonExistentTestFile = path.join(testDir, "i-am-not-here")