Problem/Motivation
The history module uses procedural functions to read and write from storage. This makes it hard for other code to alter the functioning of the history.
Proposed resolution
Introduce a HistoryRepository service.
The API interface will allow for entity types other than node to have history, but support for entity types other than node will not be implemented.
Remaining tasks
User interface changes
None.
API changes
Addition of a HistoryRepositoryInterface
Data model changes
None.