image_math: support multi-file + overwrite

[yunjunz]

Description of proposed changes

• cli.image_math: support multiple input files

• cli.image_math: add --overwrite option

• cli.asc_desc2horz_vert: check input file types, to give meaningful error msg for asc_desc2horz_vert.py does not work with timeseries #932.

• simulation.iono.iono_incidence2refraction_angle: support 3D output

• utils.utils0: add diff_wrapped_phase()

Reminders

• Pass Pre-commit check (green)
• Pass Codacy code review (green)
• Pass Circle CI test (green)
• If modifying functionality, describe changes to function behavior and arguments in a comment below the function declaration.
• If adding new functionality, add a detailed description to the documentation and/or an example.