fix: allow continue search when SearchEdit isn't focused

[BLumia]

全屏启动器行为调整，搜索框无焦点时均允许按下字母键继续搜索，按下的键会追加到搜索框内。

（其实搜索内容为空时也可以是直接往后追加，这里避免后续有别的奇怪需求，暂且分成 if else 来写）

Issue: linuxdeepin/developer-center#7627

[deepin-ci-robot]

deepin pr auto review

关键摘要:

• 代码逻辑中移除了对searchEdit.text是否为空的检查，可能会导致在searchEdit.text为空时重复添加event.text。
• searchEdit.focus的检查被移除，这意味着在baseLayer.focus为真时，无论searchEdit.focus如何都会执行switch语句。

是否建议立即修改:

• 是

建议的修改:

• 在执行searchEdit.text += event.text之前，应该检查searchEdit.text是否为空，以避免在searchEdit.text为空时重复添加文本。
• 需要恢复对searchEdit.focus的检查，以确保在baseLayer.focus为真时，只有当searchEdit.focus为真时才会执行switch语句。

[deepin-ci-robot]

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This pull-request has been approved by: BLumia, wineee

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