Update empty method guards to new style with regex (see PR).
Used clang-format 18.1.8.
New actions to validate code formatting is added.
Update .clang-format with disabling of include sorting.
It is temporary changes, then include will be sorted.
Apply formatting for /src and /tools folder.
The files with .hxx,.cxx,.lxx,.h,.pxx,.hpp,*.cpp extensions.
Refactor header file extensions from .hxx to .pxx and update include statements.
Enable handling by IDE gxx and pxx extensions as a cpp header files.
Introduce Standard_HIDDEN to hide symbols