Clean up, merge, update zh/zh-* translations and update zh-related language fallback chains in mediawiki/core.
Update zh/zh-* language fallback chain.
- Update zh-hant => zh-hans to zh-hans <=> zh-hant (unidirectional => bidirectional)
- Adding zh-hant to each zh-Hans zh-* variant fallback chain
- Adding zh to each zh-* variant fallback chain
- This also fix the Special:MyLanguage/* redirection issue
Merge zh-tw translations back to zh-hant, update zh, zh-hant, zh-tw translations and adding missing aliases in php file (namespace/special page/magic words names and aliases) in mediawiki/core.
- Merge zh-tw translations back to zh-hant
- Merge zh-tw namespace aliases
- Merge zh-tw special page names
- Merge zh-tw special page aliases
- Update zh-hant namespace names
- Update zh-hant namespace aliases
- Update zh-hant special page names
- Update zh-hant special page aliases
- Adding zh-hant translations as aliases to zh/zh-hans for fallback issues
- Update zh namespace aliases
- Update zh-hans special page aliases (moved from zh to zh-hans to prevent duplicated translation content)
- Update zh magic word default names
- Update zh magic word aliases
- Adding zh magic word default names (intended to be in en)
- Adding zh magic word aliases