test: add tests for CFF flprj files

[PProfizi]

No description provided.

[github-actions]

Some tests with 'continue-on-error: true' have failed:

• PyDPF-Post API tests on ubuntu-latest

Created by continue-on-error-comment

[PProfizi]

@rafacanton this replicates the issue for 252.
Linux: https://github.com/ansys/pydpf-core/actions/runs/18091003615/job/51471371126?pr=2640#step:21:1426
Windows: https://github.com/ansys/pydpf-core/actions/runs/18091003615/job/51471371150?pr=2640#step:21:2145

I have been able to reproduce locally.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.14%. Comparing base (ec102cb) to head (270402d).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2640      +/-   ##
==========================================
+ Coverage   84.11%   84.14%   +0.02%     
==========================================
  Files          91       91              
  Lines       10708    10709       +1     
==========================================
+ Hits         9007     9011       +4     
+ Misses       1701     1698       -3     

[rafacanton]

@rafacanton this replicates the issue for 252. https://github.com/ansys/pydpf-core/actions/runs/18091003615/job/51471371126?pr=2640#step:21:1426

I have been able to reproduce locally.

Thanks @PProfizi ! And also good to debug in Windows