Add user-configurable pagination and enhance case view filters

generic/templates/generic/partials/page_size_form.html

@@ -0,0 +1,18 @@
+<form method="get" class="row align-items-center mb-3">
+    {# Keep existing filters/searches #}
+    {% for key, value in request.GET.items %}
+        {% if key != 'per_page' %}
+            <input type="hidden" name="{{ key }}" value="{{ value }}">
+        {% endif %}
+    {% endfor %}
+    <div class="col-auto">
+        <label for="per_page" class="form-label mb-0 ">Rows per page:</label>
+    </div>
+    <div class="col-auto">
+        <select name="per_page" id="per_page" class="form-select form-select-sm" onchange="this.form.submit()">
+            {% for size in page_sizes %}
+                <option value="{{ size }}" {% if request.GET.per_page|stringformat:"s" == size|stringformat:"s" %}selected{% endif %}>{{ size }}</option>
+            {% endfor %}
+        </select>
+    </div>
+</form>