src: improve messages on CheckCast

[legendecas]

Print actual value type if the check failed.

BEGIN_COMMIT_OVERRIDE
feat: improve messages on CheckCast (#1507)
END_COMMIT_OVERRIDE

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.

Project coverage is 64.51%. Comparing base (23bb42b) to head (4cfeb29).
Report is 17 commits behind head on main.

Files	Patch %	Lines
napi-inl.h	0.00%	5 Missing ⚠️

Additional details and impacted files

@@ Coverage Diff @@## main #1507 +/- ##
==========================================
- Coverage 64.71% 64.51% -0.20% 
==========================================
Files 3 3 Lines 1981 1987 +6 Branches 687 687 ==========================================
Hits 1282 1282 - Misses 138 144 +6 
Partials 561 561 

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