Missing sharedassets0.assets file in language patch does not terminate install

Currently, if a matching `sharedassets0.assets` file is not found in the language patch, the installer will just hope for the best and use the default one.

It may be a better idea to stop the install with an error if this happens.

I think the way it works currently is that we extract the whole language patch archive directly, which automatically overwrites the sharedassets0.assets. But it may be better to leave the install as-is, without the language patch installed, if we know for sure it won't work.

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Also see #192 if this is still to be treated as a warning, not an error

查找提取语言补丁存档并处理 sharedassets0.assets 文件的代码。安装程序很可能有一个检查此文件的函数；修改它，使其在文件缺失时引发错误或停止安装。查看相关 issue #192 以了解警告与错误的背景信息。通过模拟缺少 sharedassets0.assets 文件的语言补丁进行测试。

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