add support for data tiering

[sebastianwebber]

Suggested implementation plan

Data tiering support is handled by the API call ToggleDataTiering.

Implement the missing method in the client

• add the new mutation query (example)
• implement the client function (example)
• patch other queries that query the service (example)
• update client.Service with the new fields ( dataTieringSettings.enable)

Patching the resources in Terraform events

On update

• add the conditional call in (r *ServiceResource) Update() (example)
• add tests on TestServiceResource_Default_Success

On create

• implement the on update action in the (r *ServiceResource) Create()

[minkimipt]

@sebastianwebber something similar might be needed for the the call enabling data tiering in projects:
https://github.com/timescale/savannah-projects/pull/1149