Add support for OIDC Log Level in the APIManager CRD

Currently when deploying 3scale using the operator, in order to set the OIDC Log Level in apicast, you have to set the APICAST_OIDC_LOG_LEVEL environment variable in the deployment config.

This option should be configurable from the CRD.

This is already supported in the APIcast operator but not the 3scale operator.

See oidcLogLevel: https://github.com/3scale/apicast-operator/blob/master/doc/apicast-crd-reference.md