Name 'standard' axes to match fonttools

[anthrotype]

Part of fixing https://github.com/googlefonts/fontc/issues/1020

This makes so that we follow fonttools' axis naming of a special group of registered axes, conventions still used by some old source files.

The remaining part of #1020 requires norad to support parsing of <labelname> element.

[anthrotype]

reproducer:

https://github.com/googlefonts/fontc/actions/runs/11326676896/job/31496101459?pr=1032#step:4:433

Diff < left / right > :
 [
<    "Weight",
<    "Width",
<    "Italic",
<    "Slant",
<    "Optical Size",
>    "weight",
>    "width",
>    "italic",
>    "slant",
>    "optical",
     "foobarbaz",
 ]

[anthrotype]

after this PR, https://github.com/weiweihuanghuang/Work-Sans Work-Sans-Italic.glyphs reports identical name, fvar and STAT tables in ttx_diff.py