DarkNight theme for Ghidra

[Untold]

There are still some "bugs" in the display, because actually we can't configure colors for everything :

• colors in the Symbol Tree window (function names are hard to read)
  
• background decompilation window when the cursor is in an undefined function
  
• selection in decompilation mode
  
• PCode
  
• graph window
  

https://github.com/elliiot/ghidra_darknight