[improve] AuthAthenz supports Copper Argos

[shustsud]

Motivation

• As with the Java client(cf. apache/pulsar#19445) and Go client(cf. apache/pulsar-client-go#960), make the AuthAthenz for the cpp client support Copper Argos.

Modifications

• Add the parameters x509CertChain and caCert to the ZTSClient.cc. If an X.509 certificate is passed as a parameter, it assumes Copper Argos is used and sets the X.509 certificate as a request parameter to ZTS and gets a RoleToken.

• Remove tokenExpirationTime because it is not used for the RoleToken (which is sent to Pulsar Brokers and used for authentication) but for the PrincipalToken (which is only used to get the RoleToken from ZTS). Instead I added minExpiryTime and maxExpiryTime to control the expiry time of the RoleToken in the same way as Java/Go clients.

• Existing users of this plugin will not be affected by this change.

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[hrsakai]

LGTM

[massakam]

LGTM