Refactor `translate_queryset` in MT API clients

[MizukiTemma]

Motivation

The function translate_queryset in "google_translate_api_client" and that in "deepl_api_client" are almost the same. That means there is a chance of refactoring and improvement.

Proposed Solution

Remove the duplication. For example, move the duplicated part into "machine_translation_api_client".

Alternatives

Leave as it is.

User Story

Additional Context

Bing translation is going to be added into the CMS too. It's probably better to wait for it. Do not forget SAMM.AI inherits from MachineTranslationApiClient too but has a bit different strucrure.

Design Requirements