05-Photometry/01-aperture_basics: Explain when to use aperture_photometry vs ApertureStats

[pllim]

At the time of writing, 05-Photometry/01-aperture_basics.ipynb showcases both aperture_photometry and ApertureStats. But the content isn't clear on when users should pick one over the other for their scientific use cases, especially when both return similar results.

The notebook authors are documented as @larrybradley and Lauren Chambers.