Normalize Base URL during installation

- Fix base url when is appended with a script filename
- Add default base url http://flarum.local when CLI wizard used
- Remove some code duplication
- Add minor improvement to the UX when CLI wizard used
- Add tests
- Extract base url normalisation into its own value object

src/Install/Controller/InstallController.php

@@ -13,6 +13,7 @@ namespace Flarum\Install\Controller;
 
 use Flarum\Http\SessionAuthenticator;
 use Flarum\Install\AdminUser;
+use Flarum\Install\BaseUrl;
 use Flarum\Install\DatabaseConfig;
 use Flarum\Install\Installation;
 use Flarum\Install\StepFailed;
@@ -54,16 +55,16 @@ class InstallController implements RequestHandlerInterface
     public function handle(Request $request): ResponseInterface
     {
         $input = $request->getParsedBody();
-        $baseUrl = rtrim((string) $request->getUri(), '/');
+        $baseUrl = $request->getUri();
 
         try {
             $pipeline = $this->installation
-                ->baseUrl($baseUrl)
+                ->baseUrl(BaseUrl::fromUri($baseUrl))
                 ->databaseConfig($this->makeDatabaseConfig($input))
                 ->adminUser($this->makeAdminUser($input))
                 ->settings([
                     'forum_title' => Arr::get($input, 'forumTitle'),
-                    'mail_from' => 'noreply@'.preg_replace('/^www\./i', '', parse_url($baseUrl, PHP_URL_HOST)),
+                    'mail_from' => 'noreply@'.preg_replace('/^www\./i', '', $baseUrl->getHost()),
                     'welcome_title' => 'Welcome to '.Arr::get($input, 'forumTitle'),
                 ])
                 ->build();