Xiangyu/revise fm mesh

[Xiangyu-Hu]

now all FVM cases use Vtu format, and Vtp format should be used only for surface Mesh.

Summary by Copilot:
This pull request involves significant refactoring and reorganization of the VTK I/O system for both 2D and 3D builds. The changes include removing old code, renaming files, and introducing new methods for handling VTK file writing.

The most important changes include:

Removal of Old Code:

• Removed methods related to VTK file writing from src/for_2D_build/io_system/io_vtk_fvm_2d.cpp and src/for_3D_build/io_system/io_vtk_fvm_3d.cpp. [1] [2]

Refactoring and Reorganization:

• Deleted VTK file writing methods from MeshFileHelpers in src/for_3D_build/bodies/mesh_helper_3d.cpp and src/shared/bodies/complex_bodies/mesh_helper.h. [1] [2]
• Removed io_vtk_fvm.h and added io_vtk_mesh.h in src/shared/io_system/io_all.h.

Introduction of New Methods:

• Added new methods for VTK file writing in src/shared/io_system/io_vtk_mesh.cpp under the new classes BodyStatesRecordingToMeshVtp and BodyStatesRecordingToMeshVtu. These methods include FileHeader, FileNodeCoordinates, FileInformationKey, FileCellConnectivity, FileOffsets, and FileTypeOfCell.

Code Cleanup:

• Removed old VTK I/O related code from src/shared/io_system/io_vtk_fvm.cpp.