Integrate Trace_y plugin into NanoLocz

[George-R-Heath]

Enable launching and optional data exchange between NanoLocz and the Trace_y MATLAB app (https://github.com/wfxue/Trace_y). This would allow users to pass filament AFM data from NanoLocz to Trace_y for 3D helical reconstruction.

Tasks:

• Clone or download Trace_y under plugins/Trace_y/
• Write wrapper: launch_trace_y_from_nanolocz.m
• Add button/menu item in NanoLocz to launch Trace_y
• Update README and developer documentation