FEATURE -> Queue system

[douxxtech]

This PR adds a queue system to BotWave, both on server and local client components. The queue system allows the user to create a file queue, where the next file will automatically play when the current one finishes. Usage:

  queue +file                       - Add file to queue
  queue +file1,file2                - Add multiple files
  queue +pattern_*                  - Add files matching pattern
  queue +*                          - Add all files
  queue +file!                      - Force add (skip availability checks)
  queue -file                       - Remove file from queue
  queue -*                          - Clear queue
  queue *                           - Show queue
  queue !                           - Toggle play/pause with defaults
  queue !targets                    - Toggle on specific targets
  queue !targets,freq,loop,ps,rt,pi - Toggle with custom settings
    Example: queue !all,100.5,false,"My Radio","Live",ABCD

This PR also adds the v2.0.2 of the protocol. It adds an END command, that the clients will send once they finished their broadcast.

Before merging, please make sure that everything is checked:

• The queue system works on server and local clients (add, remove, clear, auto-play, loop).
• Confirm v2.0.2 protocol update, including END command, is functional.
• Ensure scripts and assets are updated to install / update the queue system.
• Documentation and built-in help are updated
• Confirm backward compatibility for older clients.
• Closes issue FEATURE -> Broadcast all files in /opt/BotWave/uploads #33.