added new endpoints delete scanned history, delete all scanned histories, delete bookmarks, delete all bookmarks

src/main/java/com/safeqr/app/exceptions/ResourceAlreadyExists.java

@@ -0,0 +1,7 @@
+package com.safeqr.app.exceptions;
+
+public class ResourceAlreadyExists extends RuntimeException {
+    public ResourceAlreadyExists(String message){
+        super(message);
+    }
+}