refactor: Remove unused usings, use Unity asserts, small style fixes.

Assets/BossRoom/Scripts/Client/ClientInputSender.cs

-using System;
 using MLAPI;
 using UnityEngine;
 

Assets/BossRoom/Scripts/Server/Game/Action/ChaseAction.cs

-using System.Collections;
-using System.Collections.Generic;
 using UnityEngine;
 using MLAPI;
 

Assets/BossRoom/Scripts/Server/Navigation/DynamicNavPath.cs

         /// <summary>
         /// Call this to recalculate the path when the navigation mesh or dynamic obstacles changed.
         /// </summary>
-        public void OnNavMeshChanged()
+        private void OnNavMeshChanged()
         {
             RecalculatePath();
         }
         public void Clear()
         {
             m_Path.Clear();
-            ;
         }
 
         /// <summary>

Assets/BossRoom/Scripts/Server/Navigation/NavigationSystem.cs

-using NUnit.Framework;
+using UnityEngine.Assertions;
 
 namespace BossRoom.Server
 {
         /// <summary>
         /// Whether all paths need to be recalculated in the next fixed update.
         /// </summary>
-        private bool navMeshChanged;
+        private bool m_NavMeshChanged;
-            navMeshChanged = true;
+            m_NavMeshChanged = true;
-            navMeshChanged = true;
+            m_NavMeshChanged = true;
-            if (navMeshChanged)
+            if (m_NavMeshChanged)
-                navMeshChanged = false;
+                m_NavMeshChanged = false;
             }
         }
 

Assets/BossRoom/Scripts/Server/ServerCharacterMovement.cs

 using MLAPI;
-using NUnit.Framework;
-using UnityEditor;
+using UnityEngine.Assertions;
 
 namespace BossRoom.Server
 {
         {
             if (gameObject.scene.rootCount > 1) // Hacky way for checking if this is a scene object or a prefab instance and not a prefab definition.
             {
-                Assert.NotNull(
-                    GameObject.FindGameObjectWithTag(NavigationSystem.NavigationSytemTag)?.GetComponent<NavigationSystem>(),
+                Assert.IsTrue(
+                    GameObject.FindGameObjectWithTag(NavigationSystem.NavigationSytemTag)?.GetComponent<NavigationSystem>() != null,
                     $"NavigationSystem not found. Is there a NavigationSystem Behaviour in the Scene and does its GameObject have the {NavigationSystem.NavigationSytemTag} tag? {gameObject.scene.name}"
                 );
             }