PlantHolderVisualizer component system refactor (#10091)

* Converted PlantHolderVisualizer to component and system.

* Cleaned up Botany folder.

* Converted initialization of HydroTrayVisualizer under PlantHolderVisualizerSystem to it's own GenericVisualizer.

* Cleaned up hydro_tray.yml.

Content.Client/Botany/PlantHolderVisualizerSystem.cs

@@ -0,0 +1,54 @@
+using Content.Client.Botany.Components;
+using Content.Shared.Botany;
+using Robust.Client.GameObjects;
+using Robust.Shared.Utility;
+
+namespace Content.Client.Botany;
+
+public sealed class PlantHolderVisualizerSystem : VisualizerSystem<PlantHolderVisualsComponent>
+{
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeLocalEvent<PlantHolderVisualsComponent, ComponentInit>(OnComponentInit);
+    }
+
+    private void OnComponentInit(EntityUid uid, PlantHolderVisualsComponent component, ComponentInit args)
+    {
+        if (!TryComp<SpriteComponent>(uid, out var sprite))
+            return;
+
+        sprite.LayerMapReserveBlank(PlantHolderLayers.Plant);
+        sprite.LayerSetVisible(PlantHolderLayers.Plant, false);
+    }
+
+    protected override void OnAppearanceChange(EntityUid uid, PlantHolderVisualsComponent component, ref AppearanceChangeEvent args)
+    {
+        if (args.Sprite == null)
+            return;
+
+        if (args.Component.TryGetData<string>(PlantHolderVisuals.PlantRsi, out var rsi)
+            && args.Component.TryGetData<string>(PlantHolderVisuals.PlantState, out var state))
+        {
+            var valid = !string.IsNullOrWhiteSpace(state);
+
+            args.Sprite.LayerSetVisible(PlantHolderLayers.Plant, valid);
+
+            if (valid)
+            {
+                args.Sprite.LayerSetRSI(PlantHolderLayers.Plant, rsi);
+                args.Sprite.LayerSetState(PlantHolderLayers.Plant, state);
+            }
+        }
+    }
+}
+
+public enum PlantHolderLayers : byte
+{
+    Plant,
+    HealthLight,
+    WaterLight,
+    NutritionLight,
+    AlertLight,
+    HarvestLight,
+}