Problem/Motivation
While working on #2616814: Delegate all hook invocations to ModuleHandler, we discovered that workspaces_entity_load() takes its $entities argument by reference, which violates the hook_entity_load() interface.
Proposed resolution
Introduce hook_entity_load_alter() to directly solve the problem in the Workspaces module, and hook_ENTITY_TYPE_load_alter() to make this alteration behavior consistent with the other entity API hooks.
Remaining tasks
None.
User interface changes
None.
API changes
None. These are additions only.
Data model changes
None.
