Improve wordings and dots in overall the code

[sergkudinov]

Additional comments

Improves the help/error messages and function descriptions.

Agreements

• I hereby declare this contribution to be licensed under the Apache License Version 2.0, January 2004.
• I hereby agree to grant TOSIT a copyright license to use my contributions.

[PaulFarault]

Actually, we removed all try/except from the CLI as I didn't know how to properly use them. You should think about it so that we can put them everywhere.

[SteBaum]

Except these two typos everything looks good for me.

[sergkudinov]

Replaced by #503