Fix: C++20 compatibility for modern compilers (GCC 10+)

[addadi]

This pull request resolves a series of compilation errors that occur when building Micmac with modern C++ compilers (e.g., GCC 10 and newer) that enforce C++20 standards.

The build would fail at various stages, making it impossible to compile on up-to-date systems like arch linux

This PR fixes these issues by:

• Correcting deprecated constructor syntax: Updated numerous constructor definitions (Pt2d, Pt3d, Buf_Fonc_OB_TPL, etc.) from the old ClassName<Type>() form to the C++20-compliant ClassName() syntax.
• Fixing case-sensitivity typos: Corrected method calls like img.Size() to img.size().
• Resolving incorrect member access: Patched several files (Ply.h, SparseMatrix.inl) that were referring to non-existent class members.
• Consolidating fixes discussed in the community, such as those related to issue Compilation issues with code templates #255.

These changes allow Micmac to be compiled successfully with modern toolchains.

Testing:
Successfully compiled the entire project on arch linux with gcc (GCC) 15.1.1 20250425