Add function to create disciplines

+ Fix async errors
+ Extract name error

src/Middleware/error/ForwardableError.ts

@@ -1,6 +1,7 @@
 export default class ForwardableError extends Error {
   // If in different context
   private readonly __id = "CUSTOM_ERROR";
+  protected readonly __oid?: string;
 
   public readonly status: number;
 

src/Middleware/error/NotFoundError.ts

@@ -0,0 +1,13 @@
+import ForwardableError from "./ForwardableError";
+
+export default class NotFoundError extends ForwardableError {
+  protected __oid = "NOT_FOUND_ERROR";
+
+  constructor(resource?: string, pid?: string) {
+    super(404, `The requested ${resource ?? "resource"}${pid ? ` with PID '${pid}'` : ""} could not be found!`);
+  }
+
+  static isNotFoundError(err: any): err is NotFoundError {
+    return err.__oid === "NOT_FOUND_ERROR";
+  }
+}