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>

config/packages/validator.yaml

@@ -0,0 +1,11 @@
+framework:
+    validation:
+        # Enables validator auto-mapping support.
+        # For instance, basic validation constraints will be inferred from Doctrine's metadata.
+        #auto_mapping:
+        #    App\Entity\: []
+
+when@test:
+    framework:
+        validation:
+            not_compromised_password: false