feat(admin): add user role management with promotion feature

app/lang/en.json

@@ -41,6 +41,11 @@
       "TEXT": "Free text",
       "WORD": "One word",
       "CHAR": "One character"
+    },
+    "user_role": {
+      "ADMIN": "Admin",
+      "CREATOR": "Creator",
+      "USER": "Player"
     }
   },
   "error": {
@@ -131,10 +136,20 @@
       "filter_quest": "Filter pictures by quests"
     },
     "profile": {
+      "admins_and_creators": "Admins & Creators",
       "new_password": "New password",
       "no_pictures": "No pictures uploaded yet.",
       "old_password": "Old password",
-      "uploaded_pictures": "Uploaded pictures"
+      "own_role_hint": "You cannot change your own role.",
+      "promote": "Promote",
+      "promote_user": "Promote a user",
+      "role": "Role",
+      "role_changed": "Role updated!",
+      "role_change_error": "Could not change role!",
+      "role_confirm": "Do you want to change the role of {name} to {role}?",
+      "search_user": "Search user by email...",
+      "uploaded_pictures": "Uploaded pictures",
+      "user_management": "User management"
     },
     "quest": {
       "already_finalized": "Answer is already finalized, no update allowed!",