Fix xfwm4 titlebutton icon alignment, sizing and maximize-toggled state

[newman2x]

Changes

src/xfwm4/assets-svg.svg / assets-svg-Light.svg

• Fixed icon alignment and sizing inconsistencies in the source SVG
• Changed maximize-toggled button shape
• Cleaned up path coordinate precision

src/xfwm4/svg/ — all variants (standard, Light, mac, hdpi, xhdpi)

• Re-exported all individual SVG assets from the corrected source
• Includes: close, maximize, maximize-toggled, minimize (hide),
  shade, stick, menu and their active/inactive/prelight/pressed states

src/xfwm4/xpm/ — all variants (standard, hdpi, xhdpi)

• Re-rendered all XPM assets

Notes

• No changes to themerc or any other configuration files
• All variants regenerated: standard, Light, mac, hdpi, xhdpi