[FEATURE] Support the workload management via terraform

[DasMagischeToastbrot]

Is your feature request related to a problem?

Since opensearch 3.0 there is the workload management plugin available via the UI, but it would be great to have this in terraform (IaC).

What solution would you like?

Have a terraform resource where I can configure the workload management, something like:

resource "aws_opensearch_workload_management" "my-test" {
                 name           = "my-funny-workload-management"
                 description  = "this-is-my-awesome-description"
                 rules {
                              resilience_mode = "soft"/"enforced"
                              rule_prefixes = ["first-prefix", "second-prefix"...] # In the UI, there are also multiple prefixes for one rule possible sso maybe rule_prefixes= [["first-prefix","second-prefix"], ["another-prefix","blob"]]

                } 
                resource_prefix = { cpu: 100, memory: 50}
}

What alternatives have you considered?

In the meantime I'll do it in the UI, but I hope that this is just an interim solution.

Do you have any additional context?

Nope

[gaiksaya]

[Triage] @kkhatua maybe someone can take a look to add the functionality here as well?
Thanks!