Use general function for deleting AiiDA file repository

[ltalirz]

One of the things that the profile_delete function in aiida/cmdline/commands/profile.py needs to remove is the aiida file repository.

Once we support different modes of file storage (file system/object store/...) we should call the general-purpose function here.

[giovannipizzi]

Adding back to 2.0 just to make sure the delete-profile functionality does the right thing with the new-style repository

[sphuber]

Just checked that it does in fact still do the right thing, but I will take the opportunity to refactor and improve the code a bit.