Add: Validation for --url Parameter in Multisite Environment

[shubham07kb]

This pull request addresses issue #5716 by adding validation for the --url parameter in a Multisite environment. The validation checks the domain and path using the get_sites() function provided by WordPress.

Changes Made:

• Added validation for the --url parameter to check the domain and path against Multisite installations using get_sites().
• Ignored scheme check (HTTP and HTTPS) as the get_sites() function does not pass the scheme in CLI.
• Added the validation logic after WordPress is loaded, as it requires the get_sites() function, which is a WordPress function.
• This enhancement makes sure only correct site URL and path passes through --url.

Screenshot:

Similarly, work with subdirectory is we pass path.

Please review and let me know if any further changes are needed.

[swissspidy]

Thanks for the PR! 🥳
Is it possible to add some tests for this?