i18n overhaul & minor UI changes

[3gf8jv4dv]

Work in progress...

The original idea came from https://github.com/HMCL-dev/HMCL/pull/3129#issuecomment-2189541284. After reviewing the i18n files, I felt that there were some opinions, so I started working on it.

This PR should not be considered a replacement for some PR. Welcome to review and make suggestions.