Check not used messages?

[addlistener]

Is your feature request related to a problem? Please describe.
In the progress of dev, there will be a lot of locale messages not being used anymore.

Describe the solution you'd like
Maybe some mechanism to check unused messages?

[ruymon]

Hey, @addlistener! This would be an awesome feature!

Additionally, it would be incredibly useful to have a VSCode extension that allows developers to create new translation keys directly within the code. For instance, if a developer types a key that doesn't exist, the extension could suggest creating it automatically across the necessary translation files, saving time and reducing errors.

Example:

return (
  <h1>{t('tempKey')}</h1> 
  // VSCode extension suggests: "Create tempKey in translation files."
) 

This would allow for a quick workflow where upon hitting a shortcut, the missing key is auto-generated and inserted into all applicable translation files.

For example:

// en.json
{
  // ... other keys
  "tempKey": "Auto-generated"
}

// fr.json
{
  // ... other keys
  "tempKey": "Auto-generated"
}

This feature could streamline the localization process, especially for large-scale applications with multiple locales.