gh-509: Remove deprecated utils, celixbool, export and celix_utils_api

[pnoltes]

This PR removes the following deprecated headers:

• utils.h
• export.h
• celix_utils_api.h

The remaining deprecated utility headers (hash_map.h and filter.h) are scheduled for removal in a separate PR.

The current failure in the Linux apt RelWithDebInfo build appears unrelated to these changes. It is likely tied to the recently introduced GCC static analyzer causing Out-Of-Memory (OOM) issues in the build container. A fix for the CI infrastructure should be done separately.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.41%. Comparing base (78dadfa) to head (63d5302).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #829      +/-   ##
==========================================
- Coverage   91.47%   91.41%   -0.07%     
==========================================
  Files         235      235              
  Lines       28686    28686              
==========================================
- Hits        26241    26223      -18     
- Misses       2445     2463      +18     

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