feat: add GPU sharing settings to Node Template

[kasia-kujawa]

example configuration:

resource "castai_node_template" "gpu_sharing" {
    cluster_id = castai_eks_clusterid.cluster_id.id

    name             = "gpu_sharing"
    is_default       = false
    is_enabled       = true
    configuration_id = "32354e7c-adac-4b7a-b82f-cdafaf86a4ab"
    should_taint     = false

    constraints {
      on_demand = true
    }

    gpu {
      default_shared_clients_per_gpu = 5
      enable_time_sharing            = true

      sharing_configuration {
        gpu_name = "L4"
        shared_clients_per_gpu = 8
      }
      sharing_configuration {
        gpu_name = "L5"
        shared_clients_per_gpu = 2
      }
      sharing_configuration {
        gpu_name = "Tesla T4"
        shared_clients_per_gpu = 4
      }
    }
  }

Related changes in terraform module for EKS: castai/terraform-castai-eks-cluster#128