Make more message localizable

[ysc3839]

I'm adding new language to Messages.properties. However, some messages are not localizable, for example: https://github.com/FabricMC/fabric-loader/blob/d713b2a801ad142394ac0eb1d1eaa452fc783021/src/main/java/net/fabricmc/loader/impl/gui/FabricGuiEntry.java#L109 https://github.com/FabricMC/fabric-loader/blob/d713b2a801ad142394ac0eb1d1eaa452fc783021/src/main/java/net/fabricmc/loader/impl/FabricLoaderImpl.java#L190-L192 Should I make messages in exceptions localizable? Or just leave it there?

[sfPlayer1]

This area is still very WIP, I wouldn't spend too much time translating there. The overall presentation and content of these error texts isn't anywhere near it should be.

I think exceptions should remain in English for support and search reasons, but once things reach the error GUI it may be nice to offer both the English and a localized version of the text. So FormattedException needs some broader changes too.

[ysc3839]

Thanks! I will keep exceptions unchanged. I'm still going to translate Messages.properties. Although it's working in progress, I can keep it up to date. I will create two PRs these days, one is make more message localizable (for example the "Copy error" button), another is Messages.properties translated to Simplified Chinese.