Auto Translation - /api/v1/autotranslate.translateMessage never returns exception on Translation failed

Description:

The Rest API endpoint /api/v1/autotranslate.translateMessage will always return { success: true } even if the request to the translation providers is failed. This makes debugging impossible because we cannot know what is happening.

Steps to reproduce:

1. Enable Auto Translation with an API that exceeded the quota
2. Send an API request to /api/v1/autotranslate.translateMessage

Expected behavior:

A detailed error response returned

Actual behavior:

Success response returned

Server Setup Information:

• Version of Rocket.Chat Server:
• Operating System: Linux
• Deployment Method: docker
• Number of Running Instances: 1
• DB Replicaset Oplog: enabled
• NodeJS Version: 12.18.4
• MongoDB Version: 4

Client Setup Information

• Desktop App or Browser Version: Browser
• Operating System: Windows

Additional context

• DeepL's API returns error codes quite detailed https://www.deepl.com/docs-api/accessing-the-api/error-handling/. We can also monitor the remaining quota by their API https://www.deepl.com/docs-api/other-functions/monitoring-usage/
• Rocket.Chat's auto-translation API does not return any error code or error message /rocket.chat/app/autotranslate/server/deeplTranslate.js:188. Response value always is success: true

Relevant logs:

Start at rocket.chat/app/autotranslate/server/deeplTranslate.js:188 and trace the /api/v1/autotranslate.translateMessage request through the translation provider failure path. Reproduce the case with a provider quota exceeded, then verify that the endpoint returns the provider's detailed error instead of success: true.