Throw exception when fixture not found rather than ignoring.

[borgou]

Q	A
Is bugfix?	✔️
New feature?	❌
Breaks BC?	✔️
Fixed issues	when provided fixture not found(wrong namespace or use namespace like app/tests/unit/fixture, etc), there will be no warning.

[what-the-diff]

PR Summary

• Enhanced Error Handling for Missing Fixtures
  The new changes provide feedback when the system is unable to find the specified 'fixtures' or test data. The system will now throw a clear error message if you try to find fixtures in a namespace, or a specified area of the software, where none exist. This will aid in quicker error identification and resolution.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 64.48%. Comparing base (005d9f2) to head (93c2344).

Files with missing lines	Patch %	Lines
...ramework/console/controllers/FixtureController.php	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##             master   #20047   +/-   ##
=========================================
  Coverage     64.48%   64.48%           
  Complexity    11576    11576           
=========================================
  Files           433      433           
  Lines         37610    37611    +1     
=========================================
+ Hits          24252    24255    +3     
+ Misses        13358    13356    -2     

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[bizley]

Please add a changelog line, thanks.