[Fix] Improve Class-Subclass Linkage (#1846)

* Initial thoughts

* .

* Fixed linting

* Continue work on updating identifier

* Change to uuid approach

* Localization and minor fix

* Fixed CompendiumBrowser Class filter for Subclass view

* Fixed the class name display in the subclass view

* Improved missing class visual for subclass

* Fixed character creation

* Rerender class sheets when subclass link is changed

* Use compendium source over actual uuid in search

---------

Co-authored-by: Carlos Fernandez <cfern1990@gmail.com>

lang/en.json

@@ -2442,6 +2442,7 @@
                 "single": "Miss",
                 "plural": "Miss"
             },
+            "missingX": "Missing {x}",
             "maxWithThing": "Max {thing}",
             "missingDragDropThing": "Drop {thing} here",
             "multiclass": "Multiclass",
@@ -2532,6 +2533,9 @@
                     "recovery": { "label": "Recovery" },
                     "type": { "label": "Type" },
                     "value": { "label": "Value" }
+                },
+                "identifier": {
+                    "label": "Identifier"
                 }
             },
             "Ancestry": {
@@ -3219,7 +3223,6 @@
                 "subclassesAlreadyPresent": "You already have a class and multiclass subclass",
                 "noDiceSystem": "Your selected dice {system} does not have a {faces} dice",
                 "gmMenuRefresh": "You refreshed all actions and resources {types}",
-                "subclassAlreadyLinked": "{name} is already a subclass in the class {class}. Remove it from there if you want it to be a subclass to this class.",
                 "gmRequired": "This action requires an online GM",
                 "gmOnly": "This can only be accessed by the GM",
                 "noActorOwnership": "You do not have permissions for this character",