feat(cloudflare): Add TLS/SSL and email security checks for zones

[HugoPBrito]

Context

This PR adds additional security checks for Cloudflare zones, focusing on TLS/SSL configuration and email security. This is part 2 of 4 PRs for complete Cloudflare support.

Depends on: #9423

Description

Adds 9 security checks for Cloudflare zones:

TLS/SSL Checks (4):

Check	Description
zones_tls_1_3_enabled	Validates TLS 1.3 is enabled
zones_hsts_include_subdomains	Ensures HSTS includes subdomains
zones_automatic_https_rewrites_enabled	Validates automatic HTTPS rewrites are enabled
zones_universal_ssl_enabled	Ensures Universal SSL is enabled

Email Security Checks (4):

Check	Description
zones_dmarc_record_exists	Validates DMARC record exists
zones_spf_record_exists	Validates SPF record exists
zones_caa_record_exists	Validates CAA record exists
zones_email_obfuscation_enabled	Ensures email obfuscation is enabled

Security Configuration (1):

Check	Description
zones_security_level	Validates security level is appropriately configured

Steps to review

1. Review each check implementation in prowler/providers/cloudflare/services/zones/
2. Verify metadata files have correct severity and remediation guidance
3. Test locally:

   prowler cloudflare --api-token <token> --check zones_tls_1_3_enabled
   

Checklist

• Are there new checks included in this PR? Yes (9 checks)
  • If so, do we need to update permissions for the provider? No
• [x] Review if the code is being covered by tests.
• [x] Review if code is being documented following this specification https://github.com/google/styleguide/blob/gh-pages/pyguide.md#38-comments-and-docstrings
• [ ] Review if backport is needed.
• [ ] Review if is needed to change the Readme.md
• [ ] Ensure new entries are added to CHANGELOG.md, if applicable.

License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.