[DX] Config uses the term 'clear', change it to 'remove' or something more intuitive

When we created the config object we needed a method to remove a single value from within the file. Instead of using delete like Drupal had, we had to choose another word because $config->delete() will delete the entire configuration file. We chose the word clear which isn't intuitive, and sends people to the API docs to figure out what it will do.

Is it worthwhile to change this to 'remove' or is it not worth the cost of change?