fix: prevent receipt search page reload (#394)

Previously, pressing "Enter" keyboard key after typing a receipt search query on the receipt management dashboard caused the entire page to refresh due to default form submission behavior, leading to a confusing user experience. This commit fixes the issue by preventing the default page reload on search form submission.

frontend/templates/pages/receipts/_search.html

@@ -1,4 +1,4 @@
-<form method="post">
+<form method="post" onsubmit="return false">
     {% csrf_token %}
     <input type="text"
            placeholder="Search"