A lot of tests, and some improvements

Adds a lot more tests for some utility classes
Adds a new option to disable the hard-coded limitation "EnchantmentTarget.BREAKABLE" which can be useful for servers with custom items or similar.
Makes enchantment name matching case-insensitive.
Prevents an exception is enchantment name contains invalid characters.
Makes invalid objects supplied to asStringList return null instead of throwing an exception.
Uses isBlank instead of trim.isEmpty in the isEmpty method
Re-uses the random generator if calculating salvage several times

src/main/java/net/knarcraft/blacksmith/util/SalvageHelper.java

@@ -23,14 +23,16 @@ public final class SalvageHelper {
      *
      * <p>Note: Only items craft-able in a crafting table are salvageable. Netherite gear is therefore not salvageable.</p>
      *
-     * @param server         <p>The server to get recipes from</p>
-     * @param salvagedItem   <p>The item stack to salvage</p>
-     * @param ignoredSalvage <p>Any material which should not be returned as part of the salvage.</p>
+     * @param server             <p>The server to get recipes from</p>
+     * @param salvagedItem       <p>The item stack to salvage</p>
+     * @param ignoredSalvage     <p>Any material which should not be returned as part of the salvage.</p>
+     * @param limitationDisabled <p>Whether the repairable item limitation is disabled</p>
      * @return <p>The items to return to the user, or null if not salvageable</p>
      */
-    public static List<ItemStack> getSalvage(Server server, ItemStack salvagedItem, List<Material> ignoredSalvage) {
+    public static List<ItemStack> getSalvage(Server server, ItemStack salvagedItem, List<Material> ignoredSalvage,
+                                             boolean limitationDisabled) {
         if (salvagedItem == null || salvagedItem.getAmount() < 1 ||
-                !ItemHelper.isRepairable(salvagedItem)) {
+                !ItemHelper.isRepairable(salvagedItem, limitationDisabled)) {
             return null;
         }
 
@@ -71,10 +73,12 @@ public final class SalvageHelper {
             ingredients.removeIf((item) -> ignoredSalvage.contains(item.getType()));
         }
 
+        Random random = new Random();
+
         //Make sure to give salvage for all items if a stack > 1 is provided
         List<ItemStack> allSalvage = new ArrayList<>();
         for (int i = 0; i < salvagedItem.getAmount(); i++) {
-            allSalvage.addAll(getSalvage(copyItems(ingredients), salvagedItem));
+            allSalvage.addAll(getSalvage(copyItems(ingredients), salvagedItem, random));
         }
 
         return combineStacks(allSalvage);
@@ -101,15 +105,15 @@ public final class SalvageHelper {
      *
      * @param recipeItems  <p>All items required for crafting the item to salvage</p>
      * @param salvagedItem <p>The item to be salvaged</p>
+     * @param random       <p>The randomness generator to use</p>
      * @return <p>The items to be returned to the user as salvage</p>
      */
-    private static List<ItemStack> getSalvage(List<ItemStack> recipeItems, ItemStack salvagedItem) {
+    private static List<ItemStack> getSalvage(List<ItemStack> recipeItems, ItemStack salvagedItem, Random random) {
         double percentageRemaining = (ItemHelper.getDurability(salvagedItem) /
                 (double) ItemHelper.getMaxDurability(salvagedItem));
         int totalItems = totalItems(recipeItems);
         //Get the amount of recipe items to be returned
         int itemsToReturn = (int) Math.floor(percentageRemaining * totalItems);
-        Random random = new Random();
         int bound = recipeItems.size();
         List<ItemStack> salvage = new ArrayList<>();