Add lastStamp to availability and show it on people tiles

Server query extended with MAX(BU_BU) per user as LAST_STAMP,
exposed via the Availability model. Client formats it as
DD.MM. HH:mm next to the loggedIn dot, replacing the mocked time.

client/src/availability-info.ts

@@ -2,4 +2,5 @@ export class AvailabilityInfo {
   public user: string;
   public loggedIn: boolean;
   public extension: string;
+  public lastStamp: string;
 }

client/src/availability.ts

@@ -65,8 +65,13 @@ export class Availability {
       return
     }
     var dotClass = entry.loggedIn ? 'tapi-dot-on' : 'tapi-dot-off'
-    var mockedTime = '13.04. 08:30'
-    indicator.innerHTML = '<span class="tapi-dot ' + dotClass + '"></span><small>' + mockedTime + '</small>'
+    var time = ''
+    if (entry.lastStamp) {
+      var d = new Date(entry.lastStamp)
+      var pad = (n: number) => n.toString().padStart(2, '0')
+      time = pad(d.getDate()) + '.' + pad(d.getMonth() + 1) + '. ' + pad(d.getHours()) + ':' + pad(d.getMinutes())
+    }
+    indicator.innerHTML = '<span class="tapi-dot ' + dotClass + '"></span><small>' + time + '</small>'
   }
 
   private updateSquare(square: HTMLElement) {