Certman security enhancements: automated validation & OpenSSL integration

Two key enhancements have been made for more reliable and efficient security management:

Automated certificate verification

The AgentCertificateDownloader script now automatically verifies certificates using the certman verify feature. This change improves security and helps prevent deployment issues.

The script checks that:

• The certificate, private key, and CA are consistent.
• The certificate is not expired.

This verification runs during initial agent setup and automatic renewal, preventing the installation of invalid or inconsistent certificates.

Simplified certificate generation with OpenSSL syntax

Certman now natively supports OpenSSL syntax.

This enables you to use standard OpenSSL commands and parameters (such as subject, expiration, key size) directly when generating new certificates or a Certificate Authority (CA).

These enhancements provide more robust certificate verification and greater control over certificate generation.