[ResponseOps][Terraform] Update Rule resource implementation

[adcoelho]

Summary

Similar to what was done for the Maintenance Window resource, the implementation of the rule resource(elasticstack_kibana_alerting_rule) in the ElasticStack Terraform provider should be migrated from the sdkv2 to the plugin framework.

Additionally, the client used should be the kibana_oapi generated from the OpenApi specification.

[adcoelho]

Due to the complexity of this task, I think #1228 should be implemented first.