Function useGridSurface

useGridSurface(): SheetSurface | null
The SheetSurface the calling layer is rendered on, or null outside a sheet's surfaces.

Returns SheetSurface | null
Remarks
Only a layer declared on more than one surface needs it, to render the part that belongs on each:
```
const surface = useGridSurface();
if (surface === 'rowHeaders') return <MyButtons />;
if (surface === 'cells') return <MyPreview />;
return null;
```