refactor: rename all "popup" strings to "alert"

src/locales/en/translation.json

@@ -256,7 +256,7 @@
     "user_unblocked": "User has been unblocked",
     "enable_achievement_notifications": "When an achievement is unlocked",
     "launch_minimized": "Launch Hydra minimized",
-    "disable_nsfw_popup": "Disable NSFW warning popup"
+    "disable_nsfw_alert": "Disable NSFW alert"
   },
   "notifications": {
     "download_complete": "Download complete",

src/locales/pt-BR/translation.json

@@ -252,7 +252,7 @@
     "user_unblocked": "Usuário desbloqueado",
     "enable_achievement_notifications": "Quando uma conquista é desbloqueada",
     "launch_minimized": "Iniciar o Hydra minimizado",
-    "disable_nsfw_popup": "Desativar popup de conteúdo impróprio"
+    "disable_nsfw_alert": "Desativar alerta de conteúdo inapropriado"
   },
   "notifications": {
     "download_complete": "Download concluído",