Allow Olivero to be cloned by Starterkit theme generator

The new Starterkit command in Drupal 9 creates the ability to use a PHP command to create a new custom theme. Currently, the command can only clone the starterkit_theme theme. #3206217: Allow starterkit themes to control how the theme is generated → provides functionality to allow other themes to be cloned.

This issue is is to create functionality within Olivero to allow it to be cloned by Starterkit.

Things to tackle

1. We need to rename all the config in the /config directory
2. There are various places the olivero namespace is being used within JavaScript. We need to either refactor this out, or convert it to the new name.
3. The olivero namespace is also being used in the CSS (in the details component). We need to refactor/rename this.
4. Templates use the {{ attach_library('olivero/library') }} function. We need to rename this
5. The /src/OliveroPreRender.php file needs to be renamed
6. Rename and changes to the info.yml, libraries.yml files
7. Changes to function names within olivero.theme and theme-settings.php
8. I’m assuming we can just remove the olivero.post-update.php file.
9. Rename and change olivero.breakpoints.yml
10. How the heck can we test this? Ideally we need to run all of the Nightwatch and Unit tests