[ENTRIES] Implements hide_undetected option to mask missing values

[HorlogeSkynet]

Description

This patch adds a new configuration option to allow hiding "undetected entries".

Reason and / or context

This was wandering in my head for a while now. I guess minimal systems users (with a lot of empty values) may love this option (as this would allow them not to manually adapt entries object to remove unnecessary items).

How has this been tested ?

Unit tests + locally.

Types of changes :

• Bug fix (non-breaking change which fixes an issue)
• Typo / style fix (non-breaking change which improves readability)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

(partially breaking from an API point of view as __bool__ magic method Entry definition cause objects to behave differently in boolean contexts/operations)

Checklist :

• [IF NEEDED] I have updated the README.md file accordingly ;
• [IF NEEDED] I have updated the test cases (which pass) accordingly ;
• [IF BREAKING] This pull request targets next Archey version branch ;
• My changes looks good ;
• I agree that my code may be modified in the future ;
• My code follows the code style of this project (PEP8).

[ingrinder]

Sounds like a good idea, and LGTM!

(partially breaking from an API point of view as __bool__ magic method Entry definition cause objects to behave differently in boolean contexts/operations)

This seems like the more "correct" behaviour anyway 👍

[HorlogeSkynet]

Changelog and Entry unit tests updated according to __bool__ changes; Merging here, thanks ! 🙏