Add intermediate Explorer object statuses (#3696).

* Add `GetConditionsFunc` and `GetSuspendedFunc` to `ObjectKind` to simplify adding new object kinds (with updates required in a single place).

* Add showing icons for intermediate Explorer object statuses in the Explorer UI.

* Expand status and message tests for Explorer objects.

* Add unit and snapshot tests for rendering UI indicators of Explorer object statuses.

* Remove the `FluxObject` interface, `ToFluxObject` function, and adapters.

* Add returning errors from `StatusFunc` and `MessageFunc`.

* Update the comment for the `defaultStatusFunc` function to reflect changes in status computation logic logic.

* Rename `AutomatedClusterDiscoveryKind` to `AutomatedClusterDiscoveryObjectKind` for consistency.

* Add a test for computing `AutomatedClusterDiscoveryObjectKind` status message.

* Remove empty lines for consistency.

pkg/query/collector/reconciler/reconciler_test.go

@@ -258,11 +258,11 @@ func TestReconciler_Reconcile(t *testing.T) {
 				FilterFunc: func(object client.Object) bool {
 					return false
 				},
-				StatusFunc: func(obj client.Object) configuration.ObjectStatus {
-					return configuration.NoStatus
+				StatusFunc: func(_ client.Object, _ configuration.ObjectKind) (configuration.ObjectStatus, error) {
+					return configuration.NoStatus, nil
 				},
-				MessageFunc: func(obj client.Object) string {
-					return ""
+				MessageFunc: func(_ client.Object, _ configuration.ObjectKind) (string, error) {
+					return "", nil
 				},
 				Category: "test",
 			},