EntityViewsData extending classes should use $this->t() but many use t()

Problem/Motivation

Follow-up from #2509722: "Error: missing help" in Views for Node fields without descriptions.

NodeViewsData has lots of t() calls, it could use $this->t() instead since EntityViewsData uses StringTranslationTrait.

Proposed resolution

Update NodeViewsData to use $this->t() instead of t().

Check other classes that extend EntityViewsData in core and make the same change if needed.

Remaining tasks

User interface changes

API changes

Data model changes