fix(frontend): rename upgrade to plus to upgrade (#2141)

# Description

Please include a summary of the changes and the related issue. Please
also include relevant motivation and context.

## Checklist before requesting a review

Please delete options that are not relevant.

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented hard-to-understand areas
- [ ] I have ideally added tests that prove my fix is effective or that
my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged

## Screenshots (if appropriate):

frontend/public/locales/en/monetization.json

@@ -1 +1 @@
-{"upgrade":"Upgrade to plus","new":"New","manage_plan":"Manage my plan"}
+{ "upgrade": "Upgrade", "new": "New", "manage_plan": "Manage my plan" }

frontend/public/locales/es/monetization.json

@@ -1 +1,5 @@
-{"upgrade":"Actualizar a plus","new":"Nuevo","manage_plan":"Gestionar mi plan"}
+{
+  "upgrade": "Mejorar",
+  "new": "Nuevo",
+  "manage_plan": "Gestionar mi plan"
+}

frontend/public/locales/fr/monetization.json

@@ -1 +1,5 @@
-{"upgrade":"Passer à la version plus","new":"Nouveau","manage_plan":"Gérer mon plan"}
+{
+  "upgrade": "Mettre à niveau",
+  "new": "Nouveau",
+  "manage_plan": "Gérer mon plan"
+}

frontend/public/locales/pt-br/monetization.json

@@ -1 +1,5 @@
-{"upgrade":"Atualizar para o plus","new":"Novo","manage_plan":"Gerenciar meu plano"}
+{
+  "upgrade": "Atualizar",
+  "new": "Novo",
+  "manage_plan": "Gerenciar meu plano"
+}

frontend/public/locales/ru/monetization.json

@@ -1 +1,5 @@
-{"upgrade":"Обновить до плюса","new":"Новый","manage_plan":"Управлять моим планом"}
+{
+  "upgrade": "Обновить",
+  "new": "Новый",
+  "manage_plan": "Управлять моим планом"
+}

frontend/public/locales/zh-cn/monetization.json

@@ -1 +1 @@
-{"upgrade":"升级至高级版","new":"新","manage_plan":"管理我的计划"}
+{ "upgrade": "升级", "new": "新", "manage_plan": "管理我的计划" }