fix: improve compatibility of user/group existence check in package maintainer scripts

[reubenmiller]

Proposed changes

Improve the compatibility across different linux/bsd distributions when checking for the existence of users or groups during the installation and remove of thin-edge.io.

The new logic will checks for the existence of the dependent tool before using it, and if not found will continue to the next tool, the order is as follows:

1. id
2. getent
3. grep /etc/passwd (user) or grep /etc/group (groups) - Though this is only a last resort and will not work reliably on distributions that use some exotic NSS setup, like Fedora IoT, however in the majority of cases, id SHOULD be installed.

There is another related PR regarding the thin-edge.io/install.sh script which also used getent by default:

• https://github.com/thin-edge/thin-edge.io-website/pull/59

Types of changes

• [x] Bugfix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Improvement (general improvements like code refactoring that doesn't explicitly fix a bug or add any new functionality)
• [ ] Documentation Update (if none of the other choices apply)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Paste Link to the issue

https://github.com/thin-edge/thin-edge.io/issues/2941

Checklist

• [x] I have read the CONTRIBUTING doc
• [x] I have signed the CLA (in all commits with git commit -s)
• [ ] I ran cargo fmt as mentioned in CODING_GUIDELINES
• [ ] I used cargo clippy as mentioned in CODING_GUIDELINES
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have added necessary documentation (if appropriate)

Further comments

[github-actions[bot]]

Robot Results

:white_check_mark: Passed	:x: Failed	:next_track_button: Skipped	Total	Pass %	:stopwatch: Duration
453	0	3	453	100	58m4.227015s