[XGrid] XFRM: Resource Image Preview Update

<xf:css>.xgrid-resource-icon-preview { object-fit: cover; }</xf:css>
<xf:js>
(() =>
{
    'use strict';
    document.addEventListener('change', event =>
    {
        const input = event.target.closest('input[type="file"][name="upload"]');
        if (!input) return;

        const...