Cursor thickness follows font size

Summary:
Before this patch cursors (bloc, i-beam, underline)
were always drawn with 1px lines. They are now
adjusted to follow the font size.

BUG: 397986

Test Plan:
1. Open Konsole
2. Go to Edit Profile and set various font sizes and weights
3. Also mix the different cursor types
4. The cursor width should follow the font size and not
   remain always 1px wide.