Add support for the new Pre-Translation API endpoint

[andrii-bodnar]

Crowdin recently introduced a new feature that allows you to manage pre-translation queues. Also a new API endpoint has been added to the Crowdin API. We should add support for this new endpoint in the Crowdin API client.

References:

• List Pre-Translations
• Edit Pre-Translation

[IgorFroehner]

Opened a PR for this one.