Update CupertinoIcons script and regenerate the font

[LongCatIsLooong]

This patch:

Removes ligature tables Removes the glyph names from the post table

Looks like the cheatsheet and dartdoc are still using the ligatures tech. So the ligature tables are kept.

Fix overlapping outlines

Multiple SVGs with the same file name were mapped to the same codepoint, so the SVGs were imported into the same glyph.

• square_pencil_fill (create_solid) were mapped to the same glyph as square_pencil (create) ([cupertino_icons] Icons for create and create_solid from CupertinoIcons are the same (and buggy) flutter/flutter#106065). The former is mapped to 0xf418 in the patch.
• car and car_fill were using different svgs, despite the documentation claim them being the same icon ([Cupertino icons]Glyphs for car and car_fill from CupertinoIcons are broken flutter/flutter#98029). The patch treats car_fill as an alias of car to match the documentation.

A few asserts were added in the script to guard against importing multiple outlines to the same glyph.

Regenerate font

This seems to fix the vertical alignment. This should fix flutter/flutter#143069. Comparison (left: old, right: new):

[LongCatIsLooong]

This is changed from 0xf417 to 0xf418

[jmagman]

@LongCatIsLooong @xster I didn't realize we were using scripts from https://github.com/xster. Can we move this into https://github.com/flutter/packages?

[xster]

oh man, I'm a bit embarrassed that it's still here. It's definitely outlived it's shelf life. I did it here because I thought these icons would live for about 2 years like the previous design. If we think these stuff will live for a while, it'd be best to move them to somewhere more suitable long term.