[UX2.0] configuration-group unsupported_features should be empty list when nothing is configured

[tzarski0]

I am developing module for config-group. Whenever I configure a configuration group with unsupported_features set as empty list, the next terraform apply shows a diff:

  # module.sdwan.sdwan_configuration_group.configuration_group["dual_device"] will be updated in-place
  ~ resource "sdwan_configuration_group" "configuration_group" {
        id                    = "16cc4e25-8c8e-4fdc-9761-624b98d90aae"
        name                  = "dual_device"
      ~ topology_devices      = [
          ~ {
              + unsupported_features = []
                # (2 unchanged attributes hidden)
            },
          ~ {
              + unsupported_features = []
                # (2 unchanged attributes hidden)
            },
        ]
        # (4 unchanged attributes hidden)
    }

We should make sure that the reading of existing config group sets the unsupported_features correctly to empty list instead of null.

[tzarski0]

@seconroy is that something you can help with? This is blocking modules development for configuration group.