Refactor `BaseProfile` class

[Neonkraft]

1. The "searchspace_str" has to be removed from the initializer of BaseProfile. It's unintuitive.
2. The file name profile_config.py is also confusing and needs to be updated.
3. Method configure_extra has a different signature compared to the other configure_ methods.
4. get_name_wandb_run -> improve the name. The emphasis should be on the experiment name, not the "wandb name". Perhaps it's better to move this method elsewhere (having it here is what raises the need for searchspace_str in the init). The Experiment class seems like a suitable candidate.
5. The configs in _initialize_train_config_xyz are better of as config (yaml?) files which are included with the library, which are read and loaded into the BaseProfile class.
6. set_searchspace_config should has the same function but as configure_xyz but a different naming convention. Rename it.

[Neonkraft]

The configs in _initialize_train_config_xyz are better of as config (yaml?) files which are included with the library

This applies to the configs hard-coded in profiles.py too.