JobItem::getJob() can return stale job during submissions

Problem/Motivation

Noticed while working on a specific translator that had no settings during submit but they were set in the form.

Somehow, when getJob() is called during formProcessing() and then the same job item is submitted and getJob() is called again, it didn't have settings.

Proposed resolution

Always load the job from the storage, in case it was saved and the static cache was resetted. So change $this->get('tjid')->entity to Job::load($this->get('tjid')->target_id)

Technically this is a core issue but will be very hard to fix generically.

Remaining tasks

User interface changes

API changes

Data model changes