[Bug] rowSeriesNumber headerStyle与主题颜色不同步

[zundaren]

Version

1.15.2

Link to Minimal Reproduction

Steps to Reproduce

<ListTable ref="tableRef" width="100%" :height="TH"  style="margin-top: 15px" :options="{
    theme: VTable.themes.DEFAULT.extends({
      headerStyle: {
        fontSize: 14,
        bgColor: 'red',
      },
      bodyStyle: {
        borderLineWidth: 0,
      }
    }),
    rowSeriesNumber: {title: 'Seq', width: 'auto'},
    widthMode: 'autoFillWidth',
    defaultRowHeight: 40,
    autoFillHeight: false,
    autoFillWidth: false,
    hover: {disableHover: false, highlightMode: 'row'},
    tooltip: {isShowOverflowTextTooltip: true, overflowTextTooltipDisappearDelay: 10},
    select: {disableSelect : true},
    menu: {
      contextMenuItems: (field: string, row: number) => {
        return [
          { text: 'copy cmd', menuKey: 'copy_cmd' },
          { text: 'kill process', menuKey: 'kill_process' },
        ];
      }
    }

  }" :records="data" @onDropdownMenuClick="listenMenu">
    <ListColumn field="user" title="User" width="80"></ListColumn>
    <ListColumn field="cpu" title="%Cpu" width="80"></ListColumn>
  </ListTable>

Current Behavior

序号头颜色未设置时和主题自定义颜色不一致，还有bodyStyle可能也存在这样的问题，因为动态修改主题的时候，序号头颜色无法动态改变，需要把canvas销毁重新创建才行

Expected Behavior

rowSeriesNumber没有使用headerStyle的时候，期望与主题中的样式颜色保持一致，动态修改主题的时候也能保持一致

Environment

- OS:
- Browser:
- Framework:

Any additional comments?

No response