chore: Refactor Enterprise code to layer on top of AGPL (#4034)

* chore: Refactor Enterprise code to layer on top of AGPL

This is an experiment to invert the import order of the Enterprise
code to layer on top of AGPL.

* Fix Garrett's comments

* Add pointer.Handle to atomically obtain references

This uses a context to ensure the same value persists through
multiple executions to `Load()`.

* Remove entitlements API from AGPL coderd

* Remove AGPL Coder entitlements endpoint test

* Fix warnings output

* Add command-line flag to toggle audit logging

* Fix hasLicense being set

* Remove features interface

* Fix audit logging default

* Add bash as a dependency

* Add comment

* Add tests for resync and pubsub, and add back previous exp backoff retry

* Separate authz code again

* Add pointer loading example from comment

* Fix duplicate test, remove pointer.Handle

* Fix expired license

* Add entitlements struct

* Fix context passing

coderd/coderdtest/authorize_test.go

@@ -0,0 +1,20 @@
+package coderdtest_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/coder/coder/coderd/coderdtest"
+)
+
+func TestAuthorizeAllEndpoints(t *testing.T) {
+	t.Parallel()
+	client, _, api := coderdtest.NewWithAPI(t, &coderdtest.Options{
+		Authorizer:               &coderdtest.RecordingAuthorizer{},
+		IncludeProvisionerDaemon: true,
+	})
+	admin := coderdtest.CreateFirstUser(t, client)
+	a := coderdtest.NewAuthTester(context.Background(), t, client, api, admin)
+	skipRoute, assertRoute := coderdtest.AGPLRoutes(a)
+	a.Test(context.Background(), assertRoute, skipRoute)
+}