feat: Enhance error messages in vertical scaling implementation

[abhi0324]

Ⅰ. Describe what this PR does

This PR enhances error messages in the vertical scaling implementation (pkg/util/inplaceupdate/inplace_update_vertical.go) to provide more context and helpful information for developers. It improves all error messages with detailed explanations, expected formats, and troubleshooting hints without changing any functionality.

Ⅱ. Does this pull request fix one issue?

NONE

Ⅲ. Describe how to verify it

1. Compare the error messages in the updated file with the original ones
2. Run existing tests to verify that functionality remains unchanged
3. Manually test error scenarios to confirm improved error messages:
   • Try updating non-existent container resources
   • Try modifying unsupported resource types
   • Check status messages during update operations

Ⅳ. Special notes for reviews

This PR only improves error message text without modifying any functional code. Examples of improvements:

• Resource path errors now include expected format information
• Container index errors provide range information
• Resource limitations are explained with context
• Status checking errors indicate possible causes and next steps

[kruise-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 6 lines in your changes missing coverage. Please review.

Project coverage is 43.77%. Comparing base (ff8dcec) to head (dbf410f).
Report is 8 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/util/inplaceupdate/inplace_update_vertical.go	50.00%	5 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2051      +/-   ##
==========================================
- Coverage   43.78%   43.77%   -0.01%     
==========================================
  Files         316      316              
  Lines       31617    31620       +3     
==========================================
  Hits        13842    13842              
- Misses      16378    16380       +2     
- Partials     1397     1398       +1     

Flag	Coverage Δ
unittests	43.77% <50.00%> (-0.01%)	⬇️

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[ABNER-1]

Hello, @abhi0324 .

Please sign off your commit. You can refer to the following link for more details: https://github.com/openkruise/kruise/pull/2051/checks?check_run_id=42660065552

[abhi0324]

Hi @ABNER-1 , thank you for the heads-up! The DCO check has passed, and the commit is signed off. Please let me know if anything else needs to be updated.

[ABNER-1]

/lgtm