feat(AgmMarker): add rightclick support (#1443)

closes #1362

Author: s-gbz

packages/core/directives/marker.ts

@@ -115,6 +115,11 @@ export class AgmMarker implements OnDestroy, OnChanges, AfterContentInit {
    */
   @Output() markerClick: EventEmitter<void> = new EventEmitter<void>();
 
+  /**
+   * This event is fired when the user rightclicks on the marker.
+   */
+  @Output() markerRightClick: EventEmitter<void> = new EventEmitter<void>();
+
   /**
    * This event is fired when the user stops dragging the marker.
    */
@@ -214,6 +219,11 @@ export class AgmMarker implements OnDestroy, OnChanges, AfterContentInit {
     });
     this._observableSubscriptions.push(cs);
 
+    const rc = this._markerManager.createEventObservable('rightclick', this).subscribe(() => {
+      this.markerRightClick.emit(null);
+    });
+    this._observableSubscriptions.push(rc);
+
     const ds =
         this._markerManager.createEventObservable<mapTypes.MouseEvent>('dragend', this)
             .subscribe((e: mapTypes.MouseEvent) => {