sbix graphicType: flip

In macOS 14.5, I have found that FT_Load_Glyph raises an Unimplemented_Feature error with glyph index 1508 from '/System/Library/Fonts/Apple Color Emoji.ttc'. This is 'woman in manual wheelchair facing right' - https://emojipedia.org/woman_in_manual_wheelchair_facing_right

Investigating, it is hitting https://gitlab.freedesktop.org/freetype/freetype/-/blob/master/src/sfnt/ttsbit.c?ref_type=heads#L1555, as the graphicType is 'flip'. This makes some sense, as it is a flipped version of https://emojipedia.org/woman-in-manual-wheelchair

There doesn't appear to be any documentation for this type, but conceptually, this seems fairly simple. Could support be added for this?

Thanks