Some box drawing + Terminal Arrows

[Logo121]

Part of #2189.

Including ranges:

• U+1CE09 - U+1CE0A (Diagonal box drawings)
• U+1FBD0 - U+1FBD7, U+1FBDC - U+1FBDF (Diagonal lines from corner to center of edge)
  • For now its just assumed that the lines are cropped on the edge and not in the corner.
• U+1F8B8 - U+1F8BB (Diagonal arrows from bar)
  • Reimplemented the "arrow from bar" as a function instead of composing existing glyphs + bar.
  • The shafts are shrunk so that (essentially) they will not bleed out vertically.
• Temporary: U+1F8B3 (download-like arrow)
  • Implemented true to its name for now, but the actual reference graphic looks thicker and wider than that.
  • May want to revise this to follow some black arrows in Supplementary Arrows C in the future.

Other:

• U+25D9 (◙) reimplemented using difference instead of combining ◚◛ because it sometimes looks split when zoomed in.

Reference:
FairfaxHD