feat: enhance IP map visualization with custom pie-chart cluster icons and improved marker handling

- Added custom CSS for pie-chart cluster icons to improve visual representation.
- Implemented a function to create cluster icons using conic gradients based on IP categories.
- Refactored marker creation logic to utilize unique coordinates for overlapping markers.
- Introduced a loading overlay during IP data fetching to enhance user experience.
- Updated map filters to dynamically show/hide markers based on user selection.
- Improved error handling for IP stats fetching and added informative popups.

src/templates/static/css/dashboard.css

@@ -626,6 +626,11 @@ tbody {
 .marker-unknown:hover {
     box-shadow: 0 0 15px rgba(139, 148, 158, 1), inset 0 0 6px rgba(139, 148, 158, 0.7);
 }
+/* Custom pie-chart cluster icons */
+.ip-cluster-icon {
+    background: none !important;
+    border: none !important;
+}
 .leaflet-bottom.leaflet-right {
     display: none !important;
 }