Fix site deletion when ssl is not issued

[mrrobot47]

This pull request refactors the SSL certificate authorization and verification flow to improve error handling and user guidance. Instead of throwing exceptions on failed SSL operations, the code now provides clear warnings, logs actionable messages, and returns false to indicate failure. This ensures that site creation and SSL processes can fail gracefully, and users receive instructions on how to resolve issues and retry.

Error handling and user guidance improvements:

• Replaced exception throwing with warning and log messages across SSL authorization, challenge, and renewal steps in Site_Letsencrypt.php, guiding users to re-run ee site ssl-verify after fixing issues. [1] [2] [3] [4] [5] [6]
• Updated SSL registration, authorization, and verification steps in class-ee-site.php to set site_ssl to null and display warnings when failures occur, ensuring sites are created without SSL if necessary and users are informed how to proceed. [1] [2] [3]

Return value consistency:

• Standardized return values to true on success and false on failure in SSL-related methods, enabling better flow control and error handling in calling code. [1] [2] [3]

Minor code improvements:

• Fixed function documentation formatting and return type in check_www_or_non_www_domain for clarity.