[Feature request] add a debug mode

[mmahmoudian]

The problem

From time to time users are facing some errors but due to the sensitivity/confidentiality of the data, they cannot provide the input data so that I can track the issue.

The proposal

It would be convenient to have a debug argument that stores:

1. many info regarding the processes in a log file
2. store the output of every step in a RDS file so that we can have a better view on output of each step without needing to run the whole data

The 2nd item can then be later anonymized (feature names can be removed, possible residue of actual data should be stripped, and etc.) so that it make it safe to share without being concerned about the confidentiality of the data.