Projects with large number of run configurations are not manageable in QtCreator

QtCreator offers to pick run configurations from one single-column popup. This is ugly and not manageable.

Instead there should be a filesystem-like tree structure of run configurations.

It should be possible for user to sort run configurations into folders manually.

By default run configurations structure can replicate structure of CMake project. (For each add_subdirectory in CMakeLists a separate folder for run configurations should be created )