Enhance Google Test integration and add support for test projects.
Each Toolkit have GTests folder with place for new tests.
For adding new tests needs to extend FILES.cmake files in each GTests folder.
The single executable is created for each toolkit with all tests.
The tests grouped by module and toolkit with :: as separator.
Added option to download GTest by Cmake if not found.
Add GTest for PLib_JacobiPolynomial with comprehensive test cases
Add GTest for TCollection_AsciiString and TCollection_ExtendedString
Set C++ standard to C++14 for GTest compatibility if required
Reorganizing structure to have Module/TK/Package/FILES structure.
New structure reflect the structure inside IDE.
Migrate FILES, PACKAGES, EXTRLIB to CMake version to handle changes on updates.
No changes were done to installation layout, all installation result keep as before.
The migration was done using python script, see PR, which refactor automatically the structure.
Updated doc generation to have valid path to modules, toolkits and packages.
In case of PR into new version, IR-790 can be used as a target for the previous version.
