feat: remove the inner margin of dock plugin tooltips

[mhduiy]

remove the margins from the dock plugin tooltips, which will be managed uniformly by the dock

Issue: https://github.com/linuxdeepin/developer-center/issues/9997

[deepin-ci-robot]

deepin pr auto review

关键摘要:

• 在TipsWidget::setText和TipsWidget::setTextList函数中，使用fontMetrics().horizontalAdvance(m_text)替换fontMetrics().width(m_text) + 20来计算文本宽度，这是一个改进的计算方法，因为它考虑了文本的宽度而非仅仅是其宽度加上20像素。
• 在TipsWidget::paintEvent函数中，添加了option.setWrapMode(QTextOption::NoWrap);来设置文本选项，以确保文本在一行内显示完整。

是否建议立即修改:

• 是，这些修改提高了代码的可读性和性能，特别是在处理大量文本时。

[deepin-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: max-lvs, mhduiy

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[mhduiy]

/merge