feat(lh-86966): add new Terraform resource to manage users in an MSP-managed tenant

[siddhuwarrier]

Ahttps://jira-eng-rtp3.cisco.com/jira/browse/LH-86966

Description

This adds a new resource that allows an MSP portal super-admin to create users in a tenant managed
by the MSP portal.

Example usage:

data "cdo_msp_managed_tenant" "tenant" {
  name             = "CDO_tenant-name"
}

resource "cdo_msp_managed_tenant_users" "example" {
  tenant_uid = data.cdo_msp_managed_tenant.tenant.id
  users = [
    {
      username = "[email protected]",
      role = "ROLE_SUPER_ADMIN"
      api_only_user = false
    },
    {
      username = "[email protected]",
      role = "ROLE_ADMIN"
      api_only_user = false
    }
  ]
}