Bugfix/certificate_authorities: fixes for methods to interact with Hostname Associations API

[ebisso]

Description

There were flaws in the initial implementation of certificate_authorities_hostname_associations that I discovered after manually testing the changes in #3740 on real API server:

1. Parameter mtls_certificate_id was not properly added as query param in ListCertificateAuthoritiesHostnameAssociation and was not validated in the test of this method.
2. Response structure was incorrectly transposed during tests, and was missing the envelope. As such, the response failed to deserialize on the real server.

Has your change been tested?

Performed manual testing against real server
Updated Automated tests to validate both issues

Types of changes

What sort of change does your code introduce/modify?

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• This change is using publicly documented in cloudflare/api-schemas
  and relies on stable APIs.

[github-actions]

changelog detected ✅

[github-actions]

This functionality has been released in v0.112.0.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!