impr(fonts): improve letter-wise feedback of Arabic script default font (@nadalaba)

[nadalaba]

Description

• previous default Arabic-script font had ligatures that were either incorrectly shaped or failed to provide per-letter feedback within each ligature.
• that font (Vazirmatn) is now replaced with a new font (Vazirharf), which keeps the original glyph shapes of letters but renders all ligatures in their correct forms while also keeping the feedback for each individual letter of the ligature.

Vazirmatn (top) shows incorrect shapes for لأ, لإ, لآ and shows لا without letter-wise feedback. Vazirharf (bottom) has the correct shapes and letter-wise feedback for all ligatures.

• new font is stripped of Latin glyphs because it is used as fallback after other Latin fonts, so it is 56% smaller.