CJK keyboard adjustments for better Chinese input convenience

[moonbeamcelery]

• fix full-width comma
• add () to first symbol screen popups
• merge postal sign with # popups
• add = to + popup
• add full-width = to half-width popup
• fix half-width <> and single guillemets ‹›
• add check mark to square root symbol popup
• Add [] to popups
• Add pinyin characters in popup mapping

TODO:

• Consider making the full- and half-width toggle instead have three states. Add a state that is full-width for punctuation but half-width for other characters.
• Actually test

[moonbeamcelery]

Pulling in @Waelwindows for comments, because I am not sure how much this impacts Japanese input convenience.

[Waelwindows]

Looks good to me!

[moonbeamcelery]

Thanks! In that case, this is ready for merging, unless you want me to finish the three-state full/half width toggle idea in this PR.

[Waelwindows]

You could open a different PR for that