[meta] Review drupal_static conversions that use plain static variables and use the memory cache instead.

Problem/Motivation

Some of the earlier drupal_static conversions used static variables or local properties instead of the memory cache.

See #1577902-108: [META] Remove all usages of drupal_static() & drupal_static_reset()

Steps to reproduce

Review list of changes in #1577902: [META] Remove all usages of drupal_static() & drupal_static_reset()

Proposed resolution

See if some properties should be replaced with the memory cache.

Remaining tasks

Identify uses that can be updated
Create children issues.

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet