When an install has spaces but a user has no access, roadblock them

Summary:
Ref T8449. If a user doesn't have access to any spaces, most applications just don't work, and they fail in confusing ways.

Just lock users out of everything explicitly up front with a clear message instead of letting them stumble into a big broken mess.

Test Plan: Locked a user out of all spaces, saw error to that effect.

Reviewers: btrahan, eadler

Reviewed By: eadler

Subscribers: eadler, epriestley

Maniphest Tasks: T8449

Differential Revision: https://secure.phabricator.com/D13545

src/applications/spaces/controller/PhabricatorSpacesNoAccessController.php

@@ -0,0 +1,20 @@
+<?php
+
+final class PhabricatorSpacesNoAccessController
+  extends PhabricatorSpacesController {
+
+  public function handleRequest(AphrontRequest $request) {
+    return $this->newDialog()
+      ->setTitle(pht('No Access to Spaces'))
+      ->appendParagraph(
+        pht(
+          'This install uses spaces to organize objects, but your account '.
+          'does not have access to any spaces.'))
+      ->appendParagraph(
+        pht(
+          'Ask someone to add you to a Space so you can view and create '.
+          'objects.'))
+      ->addCancelButton('/', pht('Drift Aimlessly'));
+  }
+
+}