Notification system enhanced

- Base for notifcation center
- Show text in map if no data is available

frontend/src/assets/message.svg

@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" class="icon icon-tabler icon-tabler-message" width="19" height="19" viewBox="0 0 24 24" stroke-width="2" stroke="#fff" fill="none" stroke-linecap="round" stroke-linejoin="round">
+  <path stroke="none" d="M0 0h24v24H0z" fill="none"/>
+  <path d="M4 21v-13a3 3 0 0 1 3 -3h10a3 3 0 0 1 3 3v6a3 3 0 0 1 -3 3h-9l-4 4" />
+  <line x1="8" y1="9" x2="16" y2="9" />
+  <line x1="8" y1="13" x2="14" y2="13" />
+</svg>
+
+