refactor: Move checkOverlappingMarkers to utils and update import in MapComponent

- Moved checkOverlappingMarkers function from MapComponent.js to a new file in /utils/mapUtils.js for better separation of concerns.
- Updated the import statement in MapComponent.js to reflect the new location of checkOverlappingMarkers.

utils/mapUtils.js

@@ -77,3 +77,35 @@ export const restoreMapSettings = (map) => {
     }
   }
 };
+
+// Now update checkOverlappingMarkers to check if oms is initialized
+export const checkOverlappingMarkers = (map, markers, plusIcon) => {
+  // Ensure markers is always an array
+  if (!Array.isArray(markers)) {
+    //console.error("The `markers` argument is not an array:", markers);
+    return;
+  }
+
+  const overlappingGroups = {};
+
+  // Group markers by coordinates as strings
+  markers.forEach((marker) => {
+    const latlngStr = marker.getLatLng().toString();
+    if (overlappingGroups[latlngStr]) {
+      overlappingGroups[latlngStr].push(marker);
+    } else {
+      overlappingGroups[latlngStr] = [marker];
+    }
+  });
+
+  // Add plus markers at coordinates where overlaps occur
+  for (const coords in overlappingGroups) {
+    if (overlappingGroups[coords].length > 1) {
+      const latLng = L.latLng(coords.match(/[-.\d]+/g).map(Number));
+      const plusMarker = L.marker(latLng, { icon: plusIcon });
+      plusMarker.addTo(map);
+
+      //console.log("Adding plus icon marker at", latLng);
+    }
+  }
+};