fix(for-of): If there is no sizeCache when updating, assign default item size (#15549)

Author: mddragnev

projects/igniteui-angular/src/lib/directives/for-of/for_of.directive.ts

@@ -1800,7 +1800,7 @@ export class IgxGridForOfDirective<T, U extends T[] = T[]> extends IgxForOfDirec
         changes.forEachItem((item) => {
             if (item.previousIndex !== null &&
                 (numRemovedItems < 2 || !identityChanges.length || identityChanges[item.currentIndex])
-                && this.igxForScrollOrientation !== "horizontal") {
+                && this.igxForScrollOrientation !== "horizontal" && this.individualSizeCache.length > 0) {
                 // Reuse cache on those who have previousIndex.
                 // When there are more than one removed items currently the changes are not readable so ones with identity change
                 // should be racalculated.