Add two new glyphs and adjust U+22ACF for HC (post-HKSCS-2016 changes)

[tamcy]

This issue is esentially the same as adobe-fonts/source-han-sans#312 (comment) and adobe-fonts/source-han-sans#312 (comment).

In short, there are a two post-HKSCS-2016 changes:

1. Update the glyph shape of U+22ACF (𢫏).
2. New horizontal extensions to HKSCS: U+2BB37 𫬷 (⿰口騎) and U+2D25D 𭉝 (⿰口殊).

I learned that the changes were submitted and approved by the IRG (IRG N2507, IRG N2508). So I think it should be pretty safe to include them in the next version of Source Han font family.

[tamcy]

I spent some time to draw my version of the requested new glyphs in the past few months, and here I am now attaching a reference masters of the characters I came up with. Feel free to use them as a reference design or even directly. No attribution or acknowledgement is needed.

vv.mp4

Download the reference master GLIF files

I know that v2.001 has updated the glyph for U+22ACF 𢫏, so as a follow up, please see it as a request for tweaking the glyph further. As this character is "very Cantonese", non-Cantonese designers may not know its usage and expected composition very well. Here are some usage examples for comparison (above: v2.001 form, below: my attached reference form):