PLT-5380 Moved link preview image to top right corner of preview area (#5212)

* PLT-5380 Moved link preview image to top right corner of preview area for smaller images, larger and wide images are still shown below the text.

Also added logic to hide image area if image loading fails.

* Updating link previews css

webapp/tests/utils_get_nearest_point.test.jsx

@@ -24,12 +24,10 @@ describe('CommonUtils.getNearestPoint', function() {
                 nearestPointLte: {x: 1, y: 1}
             }
         ]) {
-            const nearestPointData = CommonUtils.getNearestPoint(data.pivotPoint, data.points);
+            const nearestPoint = CommonUtils.getNearestPoint(data.pivotPoint, data.points);
 
-            assert.equal(nearestPointData.nearestPoint.x, data.nearestPoint.x);
-            assert.equal(nearestPointData.nearestPoint.y, data.nearestPoint.y);
-            assert.equal(nearestPointData.nearestPointLte.x, data.nearestPointLte.x);
-            assert.equal(nearestPointData.nearestPointLte.y, data.nearestPointLte.y);
+            assert.equal(nearestPoint.x, data.nearestPoint.x);
+            assert.equal(nearestPoint.y, data.nearestPoint.y);
         }
     });
 });