Validation of user email addresses (#5434)

* Validation of user email addresses
* Improve email and password change forms

src/pretix/base/migrations/0294_user_is_verified.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.2.23 on 2025-09-04 16:06
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("pretixbase", "0293_cartposition_price_includes_rounding_correction_and_more"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="user",
+            name="is_verified",
+            field=models.BooleanField(default=False),
+        ),
+    ]