Add Warang Citi to charset_table
Add Warang Citi to charset_table

Warang Citi is used by some to write Ho (hoc). According to Wikipedia,
Latin punctuation including spaces is used, so using charset_table is
likely appropriate.
The script has a range of uppercase characters, which I mapped to the
lowercase ones.
Unicode Block: https://www.unicode.org/charts/PDF/U118A0.pdf

See issue #1970, sections "Case Alternatives" and
"Other Unsearchable Characters".

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