advancedtls: Apply defaults before version check (#8684)

advancedtls: Apply defaults before version check (#8684)

Prior to this change, creating an Options like

    tlsOpts := &advancedtls.Options{
IdentityOptions:
advancedtls.IdentityCertificateOptions{IdentityProvider: certProvider},
        // Note: Only MinTLSVersion is set, not MaxTLSVersion
        MinTLSVersion: tls.VersionTLS13,
    }

Would result in error:

    the minimum TLS version is larger than the maximum TLS version

The documentation for the Options struct states that the default for
MaxTLSVersion is TLS 1.3 but the default was being applied after
checking whether MinTLSVersion > MaxTLSVersion.

The defaults are now applied first, prior to any checks.

Fixes #8649

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