remove unused functionality to make the migration to copier easier

[ahms5]

here we can collect config parameters in cookiecutter which are not required in pyfar.
each change could be adressed in a separate issue.

for example:

• use_black
• install_libsndfile1, not need to remove anymore, see here for details
• new_project (would not be required anymore in copier)
• command_line_interface (as soon as I know we have never used it anywhere)

[ahms5]

libsndfile1 is required by e.g. the pyfar package for io stuff, so I marked it as done, because we should keep it.