perf: decrease virtual scroll render throttling to 5ms

- see SlickGrid [comment](6pac/SlickGrid#219 (comment)) for more info
- a lower thottling delay will show less blank area after scrolling to an uncached scroll position (using the scroll to position it very far down)
- NOTE: a throttling of 0ms causes flickering in some cases, but 5ms seems like a good number to use

packages/common/src/core/slickGrid.ts

@@ -275,7 +275,7 @@ export class SlickGrid<TData = any, C extends Column<TData> = Column<TData>, O e
     editorCellNavOnLRKeys: false,
     enableMouseWheelScrollHandler: true,
     doPaging: true,
-    scrollRenderThrottling: 50,
+    scrollRenderThrottling: 5,
     suppressCssChangesOnHiddenInit: false,
     ffMaxSupportedCssHeight: 6000000,
     maxSupportedCssHeight: 1000000000,

packages/common/src/interfaces/gridOption.interface.ts

@@ -739,7 +739,7 @@ export interface GridOption<C extends Column = Column> {
    */
   sanitizer?: (dirtyHtml: string) => string | TrustedHTML;
 
-  /** Defaults to 50, render throttling when scrolling large dataset */
+  /** Defaults to 5, render throttling when using virtual scroll on large dataset */
   scrollRenderThrottling?: number;
 
   /** CSS class name used when cell is selected */