Vertical screen scrolling issues

[Matriks404]

• [x] Implement smooth vertical scrolling
  • [x] Tile and character scrolling
  • [x] Smooth tile scrolling
  • [x] Fix black row of tiles during scrolling
• [x] Fix screen changing

[Matriks404]

Fixed screen changing in https://github.com/Matriks404/openSMB2/commit/34728a3d7a4d06606b4818c55345bee180709a70

[Matriks404]

Very minor backbones for smooth vertical scrolling implemented, now we need actual scrolling ;)