Can't remove country in client details

[KevoM]

Describe the bug
If you set a county in the client billing and shipping section, you can't remove it.
Crater then suppose that it should display the shipping block, because it's not empty.

Expected behavior
Many options :

1. Allow to set the country to none (good if you also don't want the country to be display in the billing bloc)
2. Allow to reset the shipping details (along the button with 'copy from billing')
3. Allow to customize in the templates (HTML/CSS/PHP) which element you want to display (whether it's set or not in the clients' details)
4. All of them 😌

Please complete the following information:

• Crater version: 6.0.6
• PHP version:
• Database type and version: 10.11.2-MariaDB

Optional info

• OS: Raspbian, Docker install
• Browser: Brave browser