style(visualizer): add icons for the new decorators

Add icons for representing RepeatForever, RepeatUntilFailure, and RepeatUntilSuccess in the
visualizer

Author: JesseTG

Assets/FluidBehaviorTree/Editor/Icons/Tasks/EventAvailable.png

@@ -4,6 +4,8 @@
 
 namespace CleverCrow.Fluid.BTs.Decorators {
     public class RepeatForever : DecoratorBase {
+        public override string IconPath { get; } = $"{PACKAGE_ROOT}/Repeat.png";
+
         protected override TaskStatus OnUpdate () {
             Child.Update();
             return TaskStatus.Continue;

Assets/FluidBehaviorTree/Editor/Icons/Tasks/EventAvailable.png.meta

@@ -4,6 +4,8 @@
 
 namespace CleverCrow.Fluid.BTs.Decorators {
     public class RepeatUntilFailure : DecoratorBase {
+        public override string IconPath { get; } = $"{PACKAGE_ROOT}/EventBusy.png";
+
         protected override TaskStatus OnUpdate () {
             if (Child.Update() == TaskStatus.Failure) {
                 return TaskStatus.Failure;

Assets/FluidBehaviorTree/Editor/Icons/Tasks/EventBusy.png

@@ -4,6 +4,8 @@
 
 namespace CleverCrow.Fluid.BTs.Decorators {
     public class RepeatUntilSuccess : DecoratorBase {
+        public override string IconPath { get; } = $"{PACKAGE_ROOT}/EventAvailable.png";
+
         protected override TaskStatus OnUpdate () {
             if (Child.Update() == TaskStatus.Success) {
                 return TaskStatus.Success;