Refactor file extension filters in CMake and QMake configurations.
Gxx extension used as a "old-way-template" to repeat .cxx content.
Marking gxx as a source file instead of header.
Moving to absolute path for the gxx integrations.
Strengthening of the criteria of the parallel status of the curves by additional checking if the ends of the curves do not diverge.
Test cases for the issue.
Automatic upgrade of OCCT code by command "occt_upgrade . -nocdl":
- WOK-generated header files from inc and sources from drv are moved to src
- CDL files removed
- All packages are converted to nocdlpack
