fix(Table): include padding in auto-fit column width (dotnetcore#6876)

* Fix column width calculation to use header cell

Updated autoFitColumnWidth to calculate the header cell width using the <th> element directly instead of querying for a child span. This ensures more accurate column width fitting when including the header.

* refactor: 更改计算 theader 宽度逻辑

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Co-authored-by: Argo Zhang <[email protected]>

Author: AApuci

src/BootstrapBlazor/Components/Table/Table.razor.js

@@ -745,7 +745,9 @@ const autoFitColumnWidth = async (table, col) => {
     if (table.options.fitColumnWidthIncludeHeader) {
         const th = col.closest('th');
         const span = th.querySelector('.table-cell');
-        maxWidth = Math.max(maxWidth, calcCellWidth(span));
+        const thStyle = getComputedStyle(th);
+        const margin = parseFloat(thStyle.getPropertyValue('padding-left')) + parseFloat(thStyle.getPropertyValue('padding-right'))
+        maxWidth = Math.max(maxWidth, calcCellWidth(span)) + margin;
     }
 
     if (table.options.autoFitColumnWidthCallback !== null) {