Existing languages was removed

[jonkan]

For example, this command removes all existing languages from BasicCatalog.xcstrings, and adds Swedish.

$ swift-translate --api-key $OPENAI_DEFAULT_API_KEY ExampleCatalogs/BasicCatalog.xcstrings --lang sv --overwrite

I think it should be very careful with removing existing languages/translations, might be irreversible.

While I might have expected the command to just add Swedish, I see the point of supporting a way to remove languages (as Xcode doesn't support this?). But maybe it would be a good idea to require explicit approval before removing?