Theme advanced options support custom option text

The terms "Privacy policy" and "Legal notice" in the theme options should support customization.

Servers and domain names within China, whether personalServers and domain names within China, whether personal your ICP registration number and must include your ICP registration number and public security registration number at the bottom of the webpage, along with links to the respective authorities.

For example:

Registration Number: Your Registration Number

The default terms are ineffective and cannot be changed.

If you agree with my suggestion, I recommend providing three advanced options for filling in content.
This is because businesses also need to display a business license, which, together with the ICP registration number and public security registration number, totals three items that can meet the real needs of both businesses and individuals.

You can check the bottom of Microsoft's Bing search engine webpage in China, where there are three record numbers, each pointing to a corresponding link.
For example: https://cn.bing.com/search?q=nextcloud&cvid=99fe6a95953c41a49d678e0dfecad3cf&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIG CAEQABhAMgYIAhAAGEAyBggDEAAYQDIGCAQQABhAMgYIBRAAGEAyBggGEAAYQDIG CAcQABhAMgYICBAAGEDSAQg1MDM0ajBqMagCAL ACAA&FORM=ANAB01&PC=U531

Thank you for reading.

Reference Links
https://github.com/nextcloud/server/issues/10024

Start by locating the theme options that render the “Privacy policy” and “Legal notice” terms, then trace how their footer links and text are configured. Done means the relevant footer entries can accept customized content and links, including the three business or registration items described in the issue; add or update focused tests if the existing theme-option tests cover this area.