Description of the new feature/enhancement

The filledBox cursor should not hide the covered character and it behaves differently for ASCII and wide characters:

• For ASCII, the cursor covers the whole character:
  
• For wide characters, the cursor only covers part of the characters:
  

Other terminal applications typically handle this well, take XShell for an example:


And the cursor automatically invert the covered character's color to show it properly without hiding it behind.