add ticket purchase page

Co-authored-by: Jan-Marlon Leibl <jleibl@proton.me>
Reviewed-on: http://git.simonis.lol/projects/abiball/pulls/13
Reviewed-by: jank1619 <jan@kjan.email>

importmap.php

@@ -16,4 +16,16 @@ return [
         'path' => './assets/app.js',
         'entrypoint' => true,
     ],
+    '@hotwired/stimulus' => [
+        'version' => '3.2.2',
+    ],
+    '@symfony/stimulus-bundle' => [
+        'path' => './vendor/symfony/stimulus-bundle/assets/dist/loader.js',
+    ],
+    '@hotwired/turbo' => [
+        'version' => '7.3.0',
+    ],
+    '@stripe/stripe-js' => [
+        'version' => '5.6.0',
+    ],
 ];