read/write/resample: improved support for GDAL complex file

[yunjunz]

Description of proposed changes

• readfile:

  • read_gdal(): add .cos to the know list (for TerraSAR-X SLC data)
  • read_binary_file(): support returning complex data using datasetName=complex.
  • read_binary_file(): move cpx_band checking to expand its applicability from isce2 to generic files, including GDAL complex files.

• resample: adjust size calculation in block-by-block IO for complex data type

• save_gdal:

  • refactor array2raster() to write_gdal(), to be consistent with utils.writefile.write() in terms of input args.
  • use readfile.DATA_TYPE_NUMPY2GDAL to support non-float32 types, such as complex64

• docs:

  • update Yunjun's contact email from Gmail to Outlook
  • README: simplify styles for Yunjun et al. (2019)
  • CONTRIBUTING: add links to the to-do list and roadmap

Reminders

• Pass Pre-commit check (green)
• Pass Codacy code review (green)
• Pass Circle CI test (green)
• Make sure that your code follows our style. Use the other functions/files as a basis.
• 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.