graphics/inkscape-open-symbols: Add new port

These symbol libraries are sets of SVG symbols located in one SVG document and
usable with Inkscape. Symbols included:

  * Google Material Design Icons
  * Github Octicons
  * Font Awesome Icons
  * Fork Awesome
  * Gnome Icon Theme Symbolic
  * Automattic Genericons
  * Taiga Icons
  * Open Iconic
  * Entypo
  * Weatherize
  * StateFace
  * EmojiOne
  * Dashicons
  * CircuiTikZ
  * Ionicons
  * SJJB Map Icons

https://github.com/PanderMusubi/inkscape-open-symbols