Add Azimuth vs Elevation Summary Plots for Multipath and CNo Analysis

[paarnes]

Add two summary plots to provide a high-level overview of antenna performance:

Multipath Summary Plot: Azimuth (X-axis), Elevation (Y-axis), Color = Mean multipath values. CNo Summary Plot: Azimuth (X-axis), Elevation (Y-axis), Color = Mean CNo values. These plots will help users quickly identify obstructions and reflection sources, simplifying antenna placement evaluation.

Requested by user (#54)