Use IMesh in mesh exchange tools

[stdcm]

• MeshExchangeMng and MeshExchanger were using DynamicMesh*.
• Move to IMesh* to be used in PolyhedralMesh.

[codecov]

Codecov Report

Attention: Patch coverage is 75.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 70.20%. Comparing base (78e8513) to head (6108aa3).
Report is 6 commits behind head on main.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...e/src/arcane/core/internal/IMeshModifierInternal.h	0.00%	1 Missing ⚠️
arcane/src/arcane/mesh/MeshExchangeMng.cc	50.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1841   +/-   ##
=======================================
  Coverage   70.20%   70.20%           
=======================================
  Files        2263     2263           
  Lines      163033   163035    +2     
  Branches    18787    18787           
=======================================
+ Hits       114463   114465    +2     
- Misses      41776    41777    +1     
+ Partials     6794     6793    -1     

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[grospelliergilles]

Good idea to remove usage of the implementation DynamicMesh.