Fix Doxygen comment style

Summary

The repository migration created to issues regarding the Doxygen comment style :

• clang-format is unable to align the Doxygen comments as it can be seen here.
• Depending on the file, Doxygen commands are prefixed with either @ or \.

What is the current bug behavior?

Inconsistent and incorrect Doxygen style.

What is the expected correct behavior?

Consistent and properly aligned Doxygen comments.

Possible fixes

• Replace the /* * */ comments with the /// alternative. This version is fully supported by clang-format and Doxygen.
• Chose either @ or / as the Doxygen prefix.