NEXTlevel7 Reloaded for Windows 7

Refreshed version of fediafedia's NEXTlevel port for 7. I fixed many small issues, bringing it in-line with the original Vista version.

Some changes include:

- Improved Start Orb with better contrast and padding

- Additional Start button style

- Improved window title contrast

- Improved dropdown glyphs: optimized for both dark and light backgrounds

- Standalone Basic and Aero versions with correct labelling

- Custom shell32

- 4K default wallpaper

Plus more!

--Update Dec. 16 2023--

Updated window taskbar buttons

Fixed taskbar gradient when taskbar position is changed

--Update Dec. 22 2023--

Updated sort header styling