fix: Fix wrong logic in update nickname and add nickname in level up notification

Author: ByteAurora

src/main/kotlin/com/github/ilovegamecoding/intellijcodexp/manager/CodeXPNotificationManager.kt

@@ -17,7 +17,10 @@ object CodeXPNotificationManager {
         notify("${codeXPChallenge.name} completed!", "Reward: ${codeXPChallenge.rewardXP} XP")
     }
 
-    fun notifyLevelUp(level: Int, xpToNextLevel: Long) {
-        notify("Level up!", "Congratulations! You are now level $level. You need $xpToNextLevel XP to reach the next level.")
+    fun notifyLevelUp(nickname: String, level: Int, xpToNextLevel: Long) {
+        notify(
+            "Level up!",
+            "Congratulations $nickname! You are now level $level. You need $xpToNextLevel XP to reach the next level."
+        )
     }
 }

src/main/kotlin/com/github/ilovegamecoding/intellijcodexp/toolWindow/CodeXPToolWindowFactory.kt

@@ -161,7 +161,7 @@ class CodeXPToolWindowFactory : ToolWindowFactory {
      * @param codeXPDashboard CodeXP dashboard.
      */
     private fun updateNickname(codeXPService: CodeXPService, codeXPDashboard: CodeXPDashboard) {
-        codeXPDashboard.tfNickname.text = codeXPService.state.nickname
+        codeXPService.state.nickname = codeXPDashboard.tfNickname.text
     }
 
     /**
@@ -180,7 +180,7 @@ class CodeXPToolWindowFactory : ToolWindowFactory {
 
         val beforeLevel = codeXPDashboard.lblCurrentLevel.text.toInt()
         if (beforeLevel != currentLevel && beforeLevel != 0) {
-            CodeXPNotificationManager.notifyLevelUp(currentLevel, xpToNextLevel)
+            CodeXPNotificationManager.notifyLevelUp(codeXPService.state.nickname, currentLevel, xpToNextLevel)
         }
 
         codeXPDashboard.lblCurrentLevel.text = StringUtil.numberToStringWithCommas(currentLevel.toLong())