Migrate the Elasticsearch script resource to the terraform-plugin-framework

[tobio]

The existing script resource (internal/elasticsearch/cluster/scriptgo) is based on the legacy TF SDKv2. We want to migrate both the resource to the Terraform Plugin Framework.

• Make sure to structure the new plugin framework based codebase consistent with the system user resource in internal/elasticsearch/security/system_user
• Make sure to copy the existing acceptance tests into the new codebase
• Make sure the existing tests pass, make sure the acceptance tests actually exercise the provider, you'll need to set the environment variable TF_ACC=1 whilst running the acceptance tests to do so.
• Add an acceptance test verifying that a legacy resource is correctly handled by the new plugin framework resource. Look at the TestAccResourceSecuritySystemUserFromSDK test in internal/elasticsearch/system_user/acc_test.go as an example of how to do this. Use 0.11.17 as the last provider version in this test.
• Add an entry to CHANGELOG.md referencing the created PR