Add logging for ecutwfc parameter handling

[coderabbitai]

Currently, the handling of the ecutwfc parameter in the write_abacus function prints information directly to the console, which can lead to excessive output. Specifically, when no valid ecutwfc candidates are found, the function defaults to 100 Ry and prints this information.

To improve user experience and debugging, it would be beneficial to log this information to a file instead of printing it to the console. This would help reduce clutter in the console output while still providing important information for debugging.

Suggested improvements:

• Add logging to a file for the ecutwfc parameter handling.
• Include a warning message when no valid ecutwfc candidates are found, such as: "Warning: No valid ecutwfc candidates found; defaulting to 100 Ry."

This feature would enhance the clarity and usability of the software, especially for users running large simulations.

PR: #79
Comment: #79 (comment)

[kirk0830]

thanks, integrating logging is a systematic refactor work and I will do it in the future. I plan to substitute all the print with logging.