Bug: Nozzle-specific load/unload aren't nozzle specific

[APz]

🐞 bug report

Affected Version(s)

Seems to be present since dual nozzle toolhead was added, happens in 4.15.2

To Reproduce

Steps to reproduce the behavior:

1. Start a print job with dual nozzle tool head
2. Pause it and observe both Left and Right nozzle having separate Unload / Load buttons
3. Press Load on left, then right nozzle
4. Both load buttons cause the current working nozzle to extrude material
5. Pressing Switch working nozzle button causes both load buttons to now attempt to load the other nozzle

Expected behavior
The GUI would suggest left nozzle's Load would attempt to load material for the left side, with the similar results for the right side button.

🌍 Your Environment

Platform:

- Operating System: Ubuntu 24.04
- Printer: Snapmaker A350