Move about dialog into separate view and add API endpoint for system info

controllers/SystemController.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Grocy\Controllers;
+
+use \Grocy\Services\ApplicationService;
+use \Grocy\Services\DatabaseMigrationService;
+use \Grocy\Services\DemoDataGeneratorService;
+
+class SystemController extends BaseController
+{
+	public function __construct(\Slim\Container $container)
+	{
+		parent::__construct($container);
+		$this->ApplicationService = new ApplicationService();
+	}
+
+	protected $ApplicationService;
+
+	public function Root(\Slim\Http\Request $request, \Slim\Http\Response $response, array $args)
+	{
+		// Schema migration is done here
+		$databaseMigrationService = new DatabaseMigrationService();
+		$databaseMigrationService->MigrateDatabase();
+
+		if (GROCY_IS_DEMO_INSTALL)
+		{
+			$demoDataGeneratorService = new DemoDataGeneratorService();
+			$demoDataGeneratorService->PopulateDemoData();
+		}
+
+		return $response->withRedirect($this->AppContainer->UrlManager->ConstructUrl('/stockoverview'));
+	}
+
+	public function About(\Slim\Http\Request $request, \Slim\Http\Response $response, array $args)
+	{
+		return $this->AppContainer->view->render($response, 'about', [
+			'system_info' => $this->ApplicationService->GetSystemInfo()
+		]);
+	}
+}