Fix: Handle Undefined Axis Property Error

[thierryc]

Fixed the problem of undefined axis.name.en

fontkit/dist/module.mjs:12699
name: axis.name.en,
                ^
TypeError: Cannot read properties of undefined (reading 'en')

Property by implementing axis tag trimming when the value is not readable.

Related to #297 #272

Font in error exemple :

https://github.com/clauseggers/Playfair/blob/master/fonts/VF-TTF/PlayfairItalicVF.ttf

output:

{
  opsz: { name: 'Optical size', min: 5, default: 1200, max: 1200 },
  wdth: { name: 'Width', min: 88, default: 88, max: 113 },
  wght: { name: 'Weight', min: 300, default: 300, max: 900 },
  ital: { name: 'ital', min: 1, default: 1, max: 1 }
}

[Typogram]

I don't think this is the right solution. This PR basically set the problemed instance name to the axisTag. This bug happens when the instance name happen to be the subFamilyName, not when it doesn't exist. It should retrieve the correct name from the name table, before fall back to axisTag as the last resort.
Fallback to axisTag as last resort is a nice add-on though!

output:

{
  ...
  ital: { name: 'ital', min: 1, default: 1, max: 1 }
}

the name should be Italic not ital, it should be the subFamilyName