refactor(filtering-row): input uses fluent type for better dd support

Author: simeonoff

projects/igniteui-angular/src/lib/grids/filtering/base/grid-filtering-row.component.html

@@ -11,7 +11,7 @@
 </igx-drop-down>
 
 <ng-template #defaultFilterUI>
-    <igx-input-group #inputGroup type="box" [displayDensity]="displayDensity" (focusout)="onInputGroupFocusout()">
+    <igx-input-group #inputGroup type="fluent" [displayDensity]="displayDensity" (focusout)="onInputGroupFocusout()">
         <igx-prefix #inputGroupPrefix
                     (click)="inputGroupPrefixClick($event)"
                     (keydown)="onPrefixKeyDown($event)"