Fix: Correct file exclusion logic in Compactor

[DealsBeam]

The file exclusion logic in the BuildWorkingFilesList method was flawed. The condition incorrectly included files for compression if their full path was present in the exclusion list, which is intended for file extensions.

This change corrects the LINQ query to ensure that files are excluded based on their extension as intended. A new test project and test case have been added to verify this fix.