feat: add cli option

[rafael145a]

Added a option to process import by cli.
It's important to avoid timeout problems.

Example of use:
wp rs-csv-importer import --file=/path/to/file.csv

[hissy]

Thank you for adding the new feature.
Could you write all of the comments in English?

[rafael145a]

Hello!
I wrote all comments and log messages in English.