formatting applied to most of the source code to tidy things up, and misc refactors

src/main/java/com/gmail/nossr50/api/exceptions/IncompleteNamespacedKeyRegister.java

@@ -1,8 +1,10 @@
 package com.gmail.nossr50.api.exceptions;
 
+import java.io.Serial;
 import org.jetbrains.annotations.NotNull;
 
 public class IncompleteNamespacedKeyRegister extends RuntimeException {
+    @Serial
     private static final long serialVersionUID = -6905157273569301219L;
 
     public IncompleteNamespacedKeyRegister(@NotNull String message) {

src/main/java/com/gmail/nossr50/api/exceptions/InvalidFormulaTypeException.java

@@ -1,6 +1,9 @@
 package com.gmail.nossr50.api.exceptions;
 
+import java.io.Serial;
+
 public class InvalidFormulaTypeException extends RuntimeException {
+    @Serial
     private static final long serialVersionUID = 3368670229490121886L;
 
     public InvalidFormulaTypeException() {

src/main/java/com/gmail/nossr50/api/exceptions/InvalidPlayerException.java

@@ -1,6 +1,9 @@
 package com.gmail.nossr50.api.exceptions;
 
+import java.io.Serial;
+
 public class InvalidPlayerException extends RuntimeException {
+    @Serial
     private static final long serialVersionUID = 907213002618581385L;
 
     public InvalidPlayerException() {

src/main/java/com/gmail/nossr50/api/exceptions/InvalidSkillException.java

@@ -1,6 +1,9 @@
 package com.gmail.nossr50.api.exceptions;
 
+import java.io.Serial;
+
 public class InvalidSkillException extends RuntimeException {
+    @Serial
     private static final long serialVersionUID = 942705284195791157L;
 
     public InvalidSkillException() {

src/main/java/com/gmail/nossr50/api/exceptions/InvalidXPGainReasonException.java

@@ -1,6 +1,9 @@
 package com.gmail.nossr50.api.exceptions;
 
+import java.io.Serial;
+
 public class InvalidXPGainReasonException extends RuntimeException {
+    @Serial
     private static final long serialVersionUID = 4427052841957931157L;
 
     public InvalidXPGainReasonException() {

src/main/java/com/gmail/nossr50/api/exceptions/McMMOPlayerNotFoundException.java

@@ -1,12 +1,15 @@
 package com.gmail.nossr50.api.exceptions;
 
+import java.io.Serial;
 import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 
 public class McMMOPlayerNotFoundException extends RuntimeException {
+    @Serial
     private static final long serialVersionUID = 761917904993202836L;
 
     public McMMOPlayerNotFoundException(@NotNull Player player) {
-        super("McMMOPlayer object was not found for [NOTE: This can mean the profile is not loaded yet! : " + player.getName() + " " + player.getUniqueId());
+        super("McMMOPlayer object was not found for [NOTE: This can mean the profile is not loaded yet! : "
+                + player.getName() + " " + player.getUniqueId());
     }
 }

src/main/java/com/gmail/nossr50/api/exceptions/ValueOutOfBoundsException.java

@@ -1,9 +0,0 @@
-package com.gmail.nossr50.api.exceptions;
-
-import org.jetbrains.annotations.NotNull;
-
-public class ValueOutOfBoundsException extends RuntimeException {
-    public ValueOutOfBoundsException(@NotNull String message) {
-        super(message);
-    }
-}