Exceptions & no user friendly message while translating a document with existing name

1. Login to CMS
2. Navigate to any un-translated document in English
3. Use translate option to translate the document to a language (example French)
4. In translate dialog, use the name that already exists (example "Test FR" and there is a document with the name "Test FR" already)

Expected - User friendly error is shown saying "The name already exists"
Actual - Action Failed (screenshot) is shown in UI and attached stack-trace is shown in terminal

This issue was found while testing CMS7-8949