Support grafana_user for cloud stack

[jaisharma639]

Feature Request

The resource (and data source) grafana_user is currently only supported for self hosted Grafana installation and doesn't work with cloud stack. The challenge being that calling the underlying api requires basic auth which isn't supported for cloud enterprise stack. With service account api token having Admin privileges, I get:
You'll need additional permissions to perform this action. Permissions needed: users:read

Use Case:

• Trying to provide RBAC at datasource level using grafana_data_source_permission requires referencing the user.id attribute. In our case, we need to lookup the user id in Grafana using users' email id

data "grafana_user" "user" {
  email    = "example@email.com"
}

data "grafana_data_source" "foo" {
  name     = "my-datasource"
}

resource "grafana_data_source_permission" "fooPermissions" {
  datasource_uid = grafana_data_source.foo.uid
  permissions {
    user_id    = grafana_user.user.id
    permission = "Edit"
  }
}

• Doing similar RBAC for dashboard folders requires looking up user id

Solution/Feature request
The api that grafana_user uses the api /api/users/lookup?loginOrEmail=example@email.com which restricts access to basic auth.

Proposal is to create another terraform resource (and data source) which uses the api /api/org/users?query=example@email.com. The resource can be named grafana_user_org or grafana_user_cloud.

Workaround:
We have used terraform http as a workaround that calls the api mentioned in proposal section. The api looks up user accepting email id and yields user id as response to be further consumed for providing RBAC to datasource.

Please let me know if this feature request is an acceptable addition to enhancing Grafana terraform. If yes, I'd like to contribute to the repository.