refactor: Add more descriptive error message for failure of vstack/extend

[coastalwhite]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 90.90909% with 1 line in your changes missing coverage. Please review.

Project coverage is 79.61%. Comparing base (b799459) to head (871b9be).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/polars-core/src/frame/mod.rs	90.90%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #20299      +/-   ##
==========================================
- Coverage   79.61%   79.61%   -0.01%     
==========================================
  Files        1565     1565              
  Lines      218319   218327       +8     
  Branches     2477     2477              
==========================================
+ Hits       173818   173822       +4     
- Misses      43935    43939       +4     
  Partials      566      566              

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