Math homoglyphs

[hal0x2328]

This PR renames several ranges listed as "COMMON" to "MATH", based on the information found in https://unicode.org/charts/PDF/U1D400.pdf

Also makes a minor change to avoid a ValueError when trying to get the category for characters that aren't in the known set, such as U+E01F0, which seems to be included in some implementations but is shown as an invalid Unicode character when I searched for it.

[orsinium]

Categories generated by generate.py based on public unicode.org data. If you made these changes by hand, they will vanish on the next synchronization, unfortunately. So, I see there 2 solutions:

1. Change the script to check if glyph name starts with "mathematical" (like MATHEMATICAL SANS-SERIF BOLD ITALIC NABLA)
2. Harder but better: contribute into unicode.org, or at least ask them why it's not a separate category.

Thank you!