tar: replace all string-based error variants with structured types

[kaladron]

Every TarError variant now carries PathBuf and/or io::Error data instead of a pre-formatted String. Add thiserror derive macros so Display implementations are generated from #[error(...)] attributes in one central place. Eliminates the last generic TarOperation and InvalidArchive string variants.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 33 lines in your changes missing coverage. Please review.
✅ Project coverage is 63.57%. Comparing base (18fa3ee) to head (02c2424).
⚠️ Report is 11 commits behind head on main.

Files with missing lines	Patch %	Lines
src/uu/tar/src/operations/create.rs	0.00%	15 Missing ⚠️
src/uu/tar/src/errors.rs	0.00%	8 Missing ⚠️
src/uu/tar/src/operations/extract.rs	0.00%	6 Missing ⚠️
src/uu/tar/src/operations/list.rs	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##           main     #149       +/-   ##
=========================================
+ Coverage      0   63.57%   +63.57%     
=========================================
  Files         0        7        +7     
  Lines         0      755      +755     
  Branches      0       24       +24     
=========================================
+ Hits          0      480      +480     
- Misses        0      275      +275     

Flag	Coverage Δ
macos_latest	63.57% <0.00%> (?)
ubuntu_latest	63.57% <0.00%> (?)
windows_latest	0.00% <0.00%> (?)

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