Implement --owner and --perms

[pvdrz]

Describe the changes done on this pull request
This PR adds the required logic to implement the --owner/-O and --perms/-P flags for visudo.

Pull Request Checklist

• I have read and accepted the code of conduct for this project.
• I have tested, formatted and ran clippy over my changes.
• I have commented and documented my changes.
• This pull request will partially issue implement visudo #657 where a proper discussion about a solution has taken place.

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: -0.19 ⚠️

Comparison is base (e1dff57) 57.66% compared to head (7efb68d) 57.48%.

❗ Current head 7efb68d differs from pull request most recent head 5b89978. Consider uploading reports for the commit 5b89978 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #689      +/-   ##
==========================================
- Coverage   57.66%   57.48%   -0.19%     
==========================================
  Files          68       69       +1     
  Lines        8960     8985      +25     
==========================================
- Hits         5167     5165       -2     
- Misses       3793     3820      +27     

Impacted Files	Coverage Δ
src/system/file/chown.rs	0.00% <0.00%> (ø)
src/system/file/lock.rs	77.04% <ø> (ø)
src/system/mod.rs	82.05% <0.00%> (-0.83%)	⬇️
src/visudo/cli.rs	0.00% <0.00%> (ø)
src/visudo/mod.rs	0.00% <0.00%> (ø)

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[github-actions]

Number of dependencies and binary size impact report

Metric	main	PR #689	Delta
Direct dependencies	3	3	-
Total dependencies	4	4	-
Binary size	996.5 KiB	996.6 KiB	-
Text size	580.6 KiB	580.3 KiB	-

Dependencies diff

 └─ sudo-rs [v0.2.0-dev.20230711]
    ├─ glob [v0.3.1]
    ├─ libc [v0.2.147]
    └─ log [v0.4.19]

[japaric]

left some comments but otherwise LGTM

[japaric]

as an alternative to this closure that gets called immediately ("pseudo try-block"), I think you could create a newtype over a locked file that releases the lock when it's dropped. so long we don't call exit from here that should release the lock even when an error occurs.

that being said, according to the glibc manual, the locks associated to a file are released when the file is closed and I think that should happen even if the process call exit because the OS should release all the resources associated to the process.