Added deprecation message in hcp consul resources and data sources

[abhishek-hashicorp]

🛠️ Description

[Note] : DO NOT MERGE before 12th Nov

Added deprecation message for the following resources and data sources for consul:

HashiCorp plans to sunset HashiCorp Consul Dedicated (HCD) in November 2025, more information about the EOL will be provided to existing customers directly

Resources:

• hcp_consul_cluster
• hcp_consul_cluster_root_token
• hcp_consul_snapshot

Data Sources:

• hcp_consul_agent_helm_config
• hcp_consul_agent_kubernetes_secret
• hcp_consul_cluster
• hcp_consul_versions

Sample warning message:

JIRA

🏗️ Acceptance tests

• Are there any feature flags that are required to use this functionality?
• Have you added an acceptance test for the functionality being added?
• Have you run the acceptance tests on this branch?

Output from acceptance testing:

$ make testacc TESTARGS='-run=TestAccXXX'

...