Backend level argument for iprof

[DonAurelio]

• We added a new flag to allow the user modifiy the backends default layering, --backend-level.

[TApplencourt]

As a compromise can you use:

    std::stringstream tokens{raw_token};
    std::string tmp;
    while (getline(tokens, tmp, ',')) {
      std::stringstream tmp_string{tmp};
      std::string k,v;
      getline(tmp_string, k, ':');
      getline(tmp_string, v);

Thamks