Properly deprecate entity_load_multiple_by_properties()

Problem/Motivation

entity_load_multiple_by_properties() is deprecated but is still used in core.

Proposed resolution

• Add @trigger_error('entity_load_multiple_by_properties() is deprecated in Drupal 8.0.x, will be removed before Drupal 9.0.0. Use the entity storage's loadByProperties() method to load an entity by their property values.', E_USER_DEPRECATED); to the method
• Replace all the usages in core

Note that there is no change record for this change originally and maybe it is in scope here to add one or maybe update https://www.drupal.org/node/2266845 → (or find a better one).

Remaining tasks

User interface changes

None

API changes

None

Data model changes

None

Release notes snippet

N/a