Add Tags support for PaaS services

[scross01]

Add support for a Tags resource and tag assignment to the PaaS service instances

Tags and Assignments REST Endpoints

Tag resource/datasource

A new Tag resource should be added to manage creation of new tags, and a Tag data source for using existing defined Tags. A Tag is uniquely defined by the key/value pair (i.e. multiple tags can have the same key) e.g.

resource "oraclepaas_tag" "example-tag1" {
  key = "environment"
  value = "qa"
}

data "oraclepaas_tag" "example-tag2" {
  key = "environment"
  value = "production"
}

Tag assignment (for discussion)

Tags are assigned to instances using the tags API, so tag the assignment relationships could be implemented as part of the Tag resource, however for a more natural usage, and consistency to tagging or other resources, the proposal is to declare the Tags are part of the instance resources (JCS, DBCS, ACCS, MySQLCS etc) and have the resource implementation use the tags api to assign and update the tag allocation, e.g.

resource "oraclepaas_mysql_service_instance" "example" {
  name               = "mysql1"
  description        = "Created by Terraform"
  ....
    
  tags = [
    "${oraclepass_tag.example-tag1.id}",
    "${data.oraclepaas_tag.example-tag2.id}"
  ]
}